Fixed typo with certain AI plans using the wrong task force variable names which resulted in AI not functioning correctly.

Fixed major bug with methods used to detect if unit is considered as a hero across certain scripts, impacted units:
* Colicoid Swarm
* Lucid Voice

Fix is not save compatible and will require a new save.
If using an ongoing save, any battle with the units listed above will need to be autoresolved otherwise the framework will crash.

Applied same extra logic as PeristentDamageGalactic.lua to improve compatibility

Fixed potential compatibility issue with other mods that alters unit XML data (has removed entries).
Added extra logic in PersistentDamageGalactic.lua script.
Ensures units listed to have persistent damage are valid by confirming it has an XML entry first.