Refactor: migrate all providers to BaseProvider ABC

[C0MPL3XDEV]

Summary

• Migrated 8 providers to BaseProvider ABC: GitHubProvider, BitlyProvider, PhoneInfoProvider, IPLocationProvider, DomainInfoProvider, MailFinderProvider, UserReconProvider, GoDorkerProvider
• Each provider implements execute(query) -> list[ProviderResult] with business logic separated from CLI I/O
• Interactive CLI wrappers preserved as thin functions calling provider classes
• Errors logged via logging instead of printed in provider logic
• Added comprehensive unit tests for all migrated providers
• Facebook and TempMail left unmigrated (deprecated API / polling pattern)

Test plan

• All tests pass (python -m pytest tests/ -v)
• Each provider tested: valid input, invalid input, empty query, network errors
• No changes to cli.py imports — backward compatible