Mods.Common Widgets

Moved over Widgets that don't require a bunch of things to move.
Extended IMove for Enter logic
Extend Enter activity class for (re)usability in enter/exit/dock logic
Avoid reading CenterPosition of invalid targets in DamageWarhead

Fixes #6642
Merge pull request #6645 from obrakmann/fix6642_tib_warhead_crash

Avoid reading CenterPosition of invalid targets in DamageWarhead
Fixed #4640 - Units teleport into transports.
Added IDisableMove
Prevent transport from moving while loading cargo
Merge pull request #6528 from atlimit8/DragIntoTransports

Modifies IMove & Enter and Fixes #4640 - Units teleport into transports
Merge pull request #6632 from steelphase-forks/common-widgets

Mods.Common Widgets
Add WithRangeCircle trait for drawing arbitrary ranges.
Add proximity trigger plumbing.
Add UpgradeActorsNear trait for passive upgrades.
Add the stealth generator to TS.
Extend INotifyOtherProduction to all actors.
Apply upgrades to units produced within range immediately.