[keyserver] Add new hashing to keyserver state check

Summary:
Part of ENG-4959
Depends on D9265
Depends on D9266

Modify the hashing on the keyserver (for new clients) so that:

• the hashes are generated from data in client-side-schema, so clients don't have to do the conversion
• the stores aren't hashed by stringifying the whole store but instead we generate a hash for each info and merge them using xor (there's a code comment explaining why that is correct)

Test Plan:
Remove the version checks and wait for state check to trigger (with an old client):

• check that there are no errors
• check that:
  • currentUserInfo hash still matches because it's not a collection and it doesn't have anything to convert
  • specific userInfos match because they don't contain anything to convert
  • all other contain different hashes than on the client
• inside of the getClientResponsesSelector additionally select integrityStore and use it's threadHashes for client side hashes -> check that now specific rawThreadInfos hashes match

Reviewers: tomek, inka, kamil

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D9267