Add SIC default credential password change prompt + migration

[acidphantasm]

Fresh install behaviour:

• credentials.json is created with default user requiring password change
• First authorize login will prompt (login shows default creds)
• Default user will not prompt again unless credentials.json is deleted

Existing install behaviour:

• Non default users will not prompt
• Default user with custom password will not prompt
• Default user with default password will prompt on first login (login shows default creds)
• Default user will not prompt again unless credentials.json is deleted (regardless of if they made the default user password spt again or custom)

This is also adjusted so the migration for the new model happens after the migration for plaintext passwords, so if they dont want to delete the credential.json but simply want to update the password in the file to plaintext they won't prompt again, it just hashes that password and then doesn't require a password change unless they flip the bool for the password change requirement to true.