Use prisma accounts in backend

[malteish]

see #1091

• store accounts in prisma instead of redis in backend
• add scripts and notes for manual migration of existing accounts (formerly sessions) from redis to prisma
• separate profile management in backend and delivery service, as the overlap now is negligible
• extend account table to include created at
• clean up libraries, improving structure. server-side and delivery saw most changes and have been detangled significantly.
• we used to have 2 files named Auth.ts and auth.ts. Imo Auth.ts handles authentication and is currently still called Auth.ts, while auth.ts handles authorization and has been renamed to authorize.ts. This starts a cleanup process that will be continued later, but this PR is already large enough.
• move socketAuth to delivery-service (from server-side), because it is used only there

[malteish]

todo: fix tests by doing the todos in these files:
https://github.com/dm3-org/dm3/blob/e14667ab8e6fe2f2ab55f6d9b56f7ac0eb2cc75f/packages/backend/src/persistence/session/setAccount.test.ts

https://github.com/dm3-org/dm3/blob/e14667ab8e6fe2f2ab55f6d9b56f7ac0eb2cc75f/packages/backend/src/persistence/session/setAccount.test.ts

@AlexNi245 maybe you can help with that? I'm having trouble finding the right words to talk to the coding gods.

[malteish]

I tested the full migration process on testing, and it worked nicely. Here are my notes from the test:

• no backend accounts or sessions
• - sign up with account 1 -> 2 signatures 
• - sign up with account 2 -> 2 signatures
• - send message between account 1 and account 2
• - backend has 2 accounts 
• - sign up with account 3 -> 2 signatures
• - backend has 3 sessions
• - accounts have no createdAt
• - deploy new version
• - backend has accounts created at 'now', and sessions
• - sign in with account 1 -> 1 signature
• - extract sessions
• - overwrite accounts
• - the account's createdAt now corresponds to the session's createdAt
• - sign in with account 2 -> 1 signature
• - sign in with account 3 -> 1 signature
• - send messages between accounts -> works
• - sign up with account 4 -> 2 signatures
• - 4 accounts, 3 sessions

We are ready to to this on staging and production next week.