Allow Mods to handle more visualization housekeeping in XComGameState_Ability

[robojumper]

The function ContextBuildVisualization does this:

VisualizeAbilityContext.InsertAbilityPerkEvents(AbilityTemplate, VisualizationTracks);
VisualizeAbilityContext.InsertAbilityFOWRevealArea(AbilityTemplate, VisualizationTracks);
VisualizeAbilityContext.InsertCinescriptCamera(VisualizationTracks);
VisualizeAbilityContext.InsertSourceUnitLookAtAction(VisualizationTracks, AbilityTemplate);

It should be opened up to mods, so they can insert their own housekeeping stuff.

[robojumper]

A use case would be in my attempt to make idle suppression animations a thing -- units should wait for that animation to finish before attempting actions. That could be solved by inserting a special wait action.