This commit was created by merging the commits presented in #39255 for
the GSoC 2020 VCS Improvement project
VCS: Make EditorVCSInterface store less amount of internal state
VCS: Add force push checkbox + more frequent VCS updates
Add force push checkbox in the Commit dock. Also add some missing
opportunities for checking the VCS state again on from UI inputs
VCS: Fix script contents not being updated on merge conflict
VCS: Add branch creation VCS interface calls
VCS: Add VCS remote creation and remote selection menus
VCS: Show more commit information + Fix truncated commit offsets
VCS: Make VCS less noisy + Fix diff view refreshes
VCS: Fix mismatched argument names in VCS helpers
VCS: Add SSH transport support for remote operations
Also, moves the editor's VCS settings registrations to
project_settings.cpp and editor_settings.cpp
VCS: Change TTR() to vformat() for branch and remote removal text
VCS: Add VCS branch icon instead of using Tree node icon
Co-authored-by: @ChronicallySerious
janglee