- Refactor email validation logic to be a service
- Use the service for both email/pass signup and Google SSO
- fix account email validation during signup
- Use `blocked_domain` setting for both email/pass signup and Google
Sign In [`BLOCKED_DOMAIN` via GlobalConfig]
- add specs for `account_builder`
- add specs for the new service
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Co-authored-by: Sojan Jose <sojan@pepalo.com>