[common] fix migration issue

[common] fix where game crashes as soon as launched: access config be…

…fore loaded

[compat/railways] if you wanna commit? split wisely

[common] Fix error where enabling fixTrackBezierSegment 'flips' the t…

…rack

[common] Fix error where enabling fixTrackBezierSegment 'flips' the t…

…rack

[flexiTrak] add option to fix wrong baked segments

Merge changes from '1.21' into 1.20

- This task is always so hard

# Conflicts:
#	modules/forge/src/main/java/com/lhwdev/minecraft/railx/mixin/common/BlockEntityTypeAccessor.java
#	modules/forge/src/main/kotlin/com/lhwdev/minecraft/railx/flexiTrack/FlexiTrackPlacement.kt
#	modules/forge/src/main/kotlin/com/lhwdev/minecraft/railx/flexiTrack/FlexiTrackPlacementClient.kt
#	modules/forge/src/main/kotlin/com/lhwdev/minecraft/railx/flexiTrack/FlexiblePlacementPacket.kt

[tooling] build tooling script

[flexiTrak] fixed whole issue; use AllItemTags instead of AllBlockTag…

…s, do not access railways classes if not loaded

[compat] fixes critical bug (#5) where compatibility mixins are loade…

…d even if targeting mod is not loaded