Begin storing branch data

[ModeratelyGreek]

Branch data and user affiliation are important prerequisites to the branch homepages feature. We must prepare ourselves to store some branch-wide data.

Plan (from William [tysm] )

• Create backend module
• Create database collection
• Create database model
• Create service class
• Create controller if needed
• Create api module
• Create api endpoint bindings

[Exanite]

Related internal discussion: https://discord.com/channels/970176225781878794/1143226536544194590/1143226536544194590