Custom house affiliations and built-in defaults

For GiveCampus school settings.

Create school custom affiliations/values for a house system, then select them on the intended forms/campaigns. Built-in GiveCampus default affiliations cannot be renamed or deleted through the normal affiliation policy. Omit an unwanted default from an individual form where allowed rather than overwriting its meaning. Review tier/leaderboard dependencies and existing data before changing displayed choices.