improvements to the script for Theodoric/Brionne (also don't run it for AI)

code clean up

Hagen:
- the chivalry units become available 1 by 1 every 10 turns to prevent spawning late game units too early

more unit_sets

added new units to missing unit_sets

Hagen:
- can spend chivalry to summon Bretonnian Knight units
- skill "Chivalry & Honour": chivalry per turn +2

Theodoric:
- when ending the turn in a region with a tavern or wine building, Theodoric gains a 5 turn buff, granting psyImmune to himself and a small morale buff for his army.
- Theodoric has a small chance to remove a negative trait when ending the turn in a region with a tavern or wine building.
- faction trait: removed "psyImmune for Lords and Paladins" and "hero action success chance"; added "-10% costs for Tavern and Wine buildings"
- adjusted starting army: -1x Peasant Mob, +1x Men At Arms (Swords)
- skill "Composition of Slaughter": AP dmg +5
- skill "Patron of Minstrels": replaced effect "Recruitment costs for Paladins" with "Construction cost for Taverns and Wine buildings"

Folcard:
- adjusted starting army: -1x Battle Pilgrims, +1x Foot Squires
Taubert:
- adjusted starting army: -1x Men At Arms (Spears), +1x Men At Arms (Swords)

- starting armies for IE, IEE and TOW are now identical
- faction selection now shows all units in a starting army (except duplicates)

adjusted scripts to no longer break when mixer is not enabled

updated for 6.3

- fixed Iselda not being able to progress her vows