In this PR:
1. Refactor guards to avoid duplicated queries: WorkspaceAuthGuard and
UserAuthGuard only check for existence of workspace and user in the
request without querying the database
Some parts of the Frontend used theme constants exported from
`modules/ui` while other parts used theme constants exported from
`twenty-ui`.
This PR centralizes theme constants by removing them from `modules/ui`
completely.
In this PR
1. Enable deletion of relation fields in the product and via the api
(migration part was missing in the api)
3. Change wording, only use "deactivate" and "delete" everywhere (and
not a mix of the two + "disable", "erase")
