[CommCoreModule] Remove userID argument from initializeCryptoAccount(...)

Summary: Context: https://linear.app/comm/issue/ENG-2601/remove-userid-arg-from-jsi-initializecryptoaccount

Test Plan:
Logged return value of initializeCryptoAccount(...) and getUserPublicKey(...) and things remain as expected.

Also went through native SIWE flow and observed that public key was properly stored in the serverDB cookies table.

Reviewers: ashoat, tomek

Reviewed By: ashoat, tomek

Differential Revision: https://phab.comm.dev/D6172