- Add `positive_only` property hint to disallow using negative presets.
These values are clamped in several places in the editor already,
so this avoids displaying presets that don't work.
- Move the Zero preset at the end of the positive list to match
the custom property editor. It's also used less often than Linear,
Ease In and Ease Out.
- Rename presets to be consistent between the easing property editor
and custom property editor.
- Remove unused `inout` hint which was redundant since it was already
the default.