refactor(budget-tool): Use supabase for budget code sharing functionality #500
Description
Is your feature request related to a problem? Please describe.
We are planning to remove the legacy firestore database, that is currently used solely for sharing budget codes. We want to keep the sharing functionality, and so need to add support within supabase for this instead
Describe the solution you'd like
Likely a single budgets table that can be used to store budget data with additional column to populate sharing code.
2 Backend endpoints to enable creating a share code (e.g. /budget/share) and importing from a code (e.g. /budget/import)
Additional context
Once migrated we should be able to convert the legacy database to readonly and mark for future deletion.