Fix server freeze on client absence.
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
Add support for generic tooltip names.
Add classic-style tooltips for TD campaign missions.
Fix bogus fence tooltip.
Add classic-style tooltips for RA campaign missions.
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
Update CurrentAdjacentCells when actor is added to the world.  Fixes #6633.
Some minor Cargo style fixes.
Merge pull request #6632 from steelphase-forks/common-widgets

Mods.Common Widgets
Move Explosion effect to Mods.Common
Move FloatingText effect to Mods.Common
Move Console commands to Mods.Common