GetCrossClassAbilities_CH
Tracking Issue: #62
The CH variant of GetCrossClassAbilities compared to vanilla does two things differently: - Adds a check to ensure that the ability to be added to the CrossClassAbilities list isn't already in the soldiers default ability tree. - This variant supersedes issue #30 by checking against the actual abilities in the current soldiers tree, instead of comparing against all the potential abilities the soldier could have had available. This is especially important when classes uses the RandomAbilityDecks, since otherwise in the worst case scenario, you could end up with no available cross class abilities.
The old function is kept in case mods call it, but is otherwise ignored throughout the XComGame codebase