Consolidate TS types

[jescalada]

Is your feature request related to a problem? Please describe.
After the TS refactors Some types such as RepoData and Action are repeated and sometimes contain different fields. We want to consolidate/clean up the various types in the project so that there's a single source of truth between the UI, API and DB.

Describe the solution you'd like
Maybe a shared/types.ts file could contain all the types shared across the project? And then removing the various duplicates and moving all the types to that file.