Old Code Revamp, Curved Rails, & Actor To Rail Fix

Curved Rails can be created and their curve control point can be moved in the viewport when a point is selected.
Overlapping rail points is possible now
Adding layers is now possible (limits to the amount of Play/DecoArea layers)
WIP Deleting Layers
Fixes
Fixed crash with loading bone params
Fixed how Actor To Rail Links are saved, as the previous method caused bugs with objects that moved along them automatically.
Legacy ImGui Column code rewritten with the newer API's ImGui Table code.
Tweaked the UI of Actor to Rail Link and Local Links window
Fixed selecting Tile Units, Rails, and Global Links via the UI windows
Fixed batch undo when deleting multiple objects

shibbo / Fushigi