Ability to force specific faction flags for all factions

[ninjakitty844]

Is your feature request related to a problem? Please describe.
There are certain faction flags that I want to be always enabled for all factions. For example, friendly fire.

I want friendly fire enabled for all factions so that there can be brawls and thievery within factions (can't catch a thief if you can't hurt them!). But this doesn't work if someone can just disable it for their individual faction.

Describe the solution you'd like
I would like for the config to accept a list of flags that will always stay at their default value.

Maybe could be integrated into the default flags setting like this:

flags:
defaults:
protectVillagerTrade: true
alliesCanInteractWithLand: false
vassalageTreeCanInteractWithLand: true
liegeChainCanInteractWithLand: true
neutral: false
color: random # Can be hex colours, e.g. '#ffffff', '#ffcc00', etc., or 'random' to choose a random colour
allowFriendlyFire: true
acceptBonusPower: true
permanent:
allowFriendlyFire
neutral

(this would make it so that allowFriendlyFire is always true for all factions, and neutral is always false for all factions)