Tweak editor icons for navigation nodes and SkeletonIK3D

This adds a partial 2D/3D color to each icon for easier visual grepping.
The icons are not fully colored as these nodes don't inherit from
Node2D or Node3D. This is similar in principle to how the
WorldEnvironment editor icon is colored.

editor/icons/NavigationAgent2D.svg

@@ -1 +1 @@
-<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><path d="m8 1c-3 0-5 2-5 5s3 6 5 9c2-3 5.007-6.03 5-9 0-3-2-5-5-5zm0 2.5c1.371 0 2.5 1.129 2.5 2.5s-1.129 2.5-2.5 2.5-2.5-1.129-2.5-2.5 1.129-2.5 2.5-2.5z" fill="#e0e0e0" fill-rule="nonzero"/></svg>
+<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><path d="m8 1v2.5c1.371 0 2.5 1.129 2.5 2.5s-1.129 2.5-2.5 2.5v6.5c2-3 5.007-6.03 5-9 0-3-2-5-5-5z" fill="#8da5f3" fill-opacity=".988235"/><path d="m8 1c-3 0-5 2-5 5s3 6 5 9v-6.5c-1.371 0-2.5-1.129-2.5-2.5s1.129-2.5 2.5-2.5z" fill="#e0e0e0"/></svg>

editor/icons/NavigationAgent3D.svg

@@ -1 +1 @@
-<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><g fill-rule="nonzero"><path d="m9 1c-1.371 0-2.308.429-2.939 1.074-.668.663-1.34 1.324-2.01 1.985-.046 1.741.757 4.327 2.365 4.843.178.317.384.649.584.977v5.121l2-2c2-3 4-6 4-8s-1-4-4-4z" fill="#fff" fill-opacity=".39"/><path d="m7 3c-3 0-4 2-4 4s2 5 4 8c2-3 4-6 4-8s-1-4-4-4zm0 2c1.097 0 2 .903 2 2s-.903 2-2 2-2-.903-2-2 .903-2 2-2z" fill="#e0e0e0"/></g></svg>
+<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><g fill-rule="nonzero"><path d="m8 1.0859375c-.8454344.1560829-1.4755929.5141293-1.9394531.9882813-.668.663-1.3397656 1.323375-2.0097657 1.984375-.046 1.7409999.7572344 4.32775 2.3652344 4.84375.178.317.3839844.6485624.5839844.9765624v5.1210938l1-1z" fill="#e0e0e0" fill-opacity=".501961"/><path d="m7 3c-3 0-4 2-4 4s2 5 4 8c.3378629-.506794.671779-1.011698 1-1.513672v-4.7597655c-.2952789.1727801-.6361816.2734375-1 .2734375-1.097 0-2-.903-2-2s.903-2 2-2c.3638184 0 .7047211.1006574 1 .2734375v-2.1894531c-.3055959-.054762-.6378835-.0839844-1-.0839844z" fill="#e0e0e0"/><g fill="#fc7f7f"><path d="m9 1c-.3631515 0-.6953702.0296972-1 .0859375v12.9140625l1-1c2-3 4-6 4-8s-1-4-4-4z" fill-opacity=".501961"/><path d="m8 3.0839844v2.1894531c.5950581.3481936 1 .9933809 1 1.7265625s-.4049419 1.3783689-1 1.7265625v4.7597655c1.6147033-2.469489 3-4.8241909 3-6.486328 0-1.758589-.773848-3.5170952-3-3.9160156z"/></g></g></svg>

editor/icons/NavigationObstacle2D.svg

@@ -1 +1 @@
-<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><path d="m8 .875c-.625 0-1.25.375-1.5 1.125l-3 10h9l-3-10c-.25-.75-.875-1.125-1.5-1.125zm-1.5 4.125h3l1 4h-5zm-4.5 8c-1 0-1 2 0 2h12c1 0 1-2 0-2z" fill="#e0e0e0" fill-rule="nonzero"/></svg>
+<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><path d="m8 .875c-.625 0-1.25.375-1.5 1.125l-3 10h4.5v-3h-2.5l1-4h1.5zm-6 12.125c-1 0-1 2 0 2h6v-2z" fill="#e0e0e0"/><path d="m8 .875v4.125h1.5l1 4h-2.5v3h4.5l-3-10c-.25-.75-.875-1.125-1.5-1.125zm0 12.125v2h6c1 0 1-2 0-2z" fill="#8da5f3" fill-opacity=".988235"/></svg>

editor/icons/NavigationObstacle3D.svg

@@ -1 +1 @@
-<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><g fill-rule="nonzero"><path d="m4.607 8.379c-1.798.928-3.607 2.072-3.607 2.621 0 1 6 4 7 4s7-3 7-4c0-.549-1.809-1.693-3.607-2.621l.607 1.621c2 4-10 4-8 0z" fill="#fff" fill-opacity=".39"/><path d="m8 .875c-.375 0-.75.375-1 1.125l-3 8c-2 4 10 4 8 0l-3-8c-.25-.75-.625-1.125-1-1.125zm-1.5 4.125c1 .5 2 .5 3 0l1 3.5c-1.5 1-3.5 1-5 0z" fill="#e0e0e0"/></g></svg>
+<svg clip-rule="evenodd" fill-rule="evenodd" stroke-linejoin="round" stroke-miterlimit="2" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg"><g fill-rule="nonzero"><path d="m4.6074219 8.3789062c-1.798.9280001-3.6074219 2.0720938-3.6074219 2.6210938 0 1 6 4 7 4v-2c-2.5 0-5-1-4-3z" fill="#e0e0e0" fill-opacity=".501961"/><path d="m8 .875c-.375 0-.75.375-1 1.125l-3 8c-1 2 1.5 3 4 3v-3.75c-.875 0-1.75-.25-2.5-.75l1-3.5c.5.25 1 .375 1.5.375z" fill="#e0e0e0"/><g fill="#fc7f7f"><path d="m11.392578 8.3789062.607422 1.6210938c1.002342 2.004685-1.511742 3.004696-4.0175781 3v1.998047c.0053893.000157.0124503.001953.0175781.001953 1 0 7-3 7-4 0-.549-1.809422-1.6930938-3.607422-2.6210938z" fill-opacity=".501961"/><path d="m8 .875c-.00585 0-.011729.001771-.017578.001953v4.498047c.5058535.0029611 1.0117243-.1220732 1.517578-.375l1 3.5c-.7550159.5033439-1.6367318.7533663-2.5175781.75v3.75c2.5058361.004696 5.0199201-.995315 4.0175781-3l-3-8c-.25-.75-.625-1.125-1-1.125z"/></g></g></svg>

editor/icons/SkeletonIK3D.svg

@@ -1 +1 @@
-<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m6 2a4 4 0 0 0 -4 4 4 4 0 0 0 2 3.4531v3.5469a2 2 0 0 0 1 1.7324 2 2 0 0 0 1 .26562v.001953h4v-.001953a2 2 0 0 0 1-.26562 2 2 0 0 0 1-1.7324v-3.5469a4 4 0 0 0 2-3.4531 4 4 0 0 0 -4-4zm-1 3a1 1 0 0 1 1 1 1 1 0 0 1 -1 1 1 1 0 0 1 -1-1 1 1 0 0 1 1-1zm6 0a1 1 0 0 1 1 1 1 1 0 0 1 -1 1 1 1 0 0 1 -1-1 1 1 0 0 1 1-1zm-4 2h2v1h-2zm-2 2h1v1h1v-1h1 1v1h1v-1h1v.86719 3.1328h-1v-1h-1v1h-1-1v-1h-1v1h-1v-3.1309-.86914z" fill="#e0e0e0"/></svg>
+<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m6 2a4 4 0 0 0 -4 4 4 4 0 0 0 2 3.453125v3.546875a2 2 0 0 0 1 1.732422 2 2 0 0 0 1 .265625v.001953h2v-2h-1v-1h-1v1h-1v-3.1308594-.8691406h1v1h1v-1h1v-1h-1v-1h1v-5zm-1 3a1 1 0 0 1 1 1 1 1 0 0 1 -1 1 1 1 0 0 1 -1-1 1 1 0 0 1 1-1z" fill="#e0e0e0"/><path d="m8 2v5h1v1h-1v1h1v1h1v-1h1v.8671875 3.1328125h-1v-1h-1v1h-1v2h2v-.001953a2 2 0 0 0 1-.265625 2 2 0 0 0 1-1.732422v-3.546875a4 4 0 0 0 2-3.453125 4 4 0 0 0 -4-4zm3 3a1 1 0 0 1 1 1 1 1 0 0 1 -1 1 1 1 0 0 1 -1-1 1 1 0 0 1 1-1z" fill="#fc7f7f"/></svg>