Make custom OuiJournalPages + CollabMapDataProcessor public, add api for per-collab journal page editing

[aonkeeper4]

Makes things required to make custom collab journal pages public and adds an API to allow code mods to edit collab journals on a per-collab basis.

[aonkeeper4]

A couple things I'm not sure about:

• Should the new heart sprite override behaviour stay in this PR or be moved to a separate one (which would maybe also include a way to change the lobby map heart sprite independently of the lobby heart sprite, not sure if that's necessary yet)?
• Should the methods in OuiJournalCollabProgressDashCountMod be made public? This would make them cleaner to use in custom journal pages but would require changing DashCountMod.

[maddie480]

I'm fine with both things staying in the same PR, and I'm also fine with making the dash count mod-related methods public 👍