feat(registry): onboard registry service

[martinezmo]

Description

• Auto-generated Registry code.
• Include required meta files (RELEASE.md, VERSION, CHANGELOG.md)
• Implement waiters.
• Create examples

JIRA issue: https://jira.schwarz/browse/STACKITCRE-80

Checklist

• Issue was linked above
• No generated code was adjusted manually (check comments in file header)
• Changelogs
  • Changelog in the root directory was adjusted (see here)
  • Changelog(s) of the service(s) were adjusted (see e.g. here)
• VERSION file(s) of the service(s) were adjusted
• Code format was applied: make fmt
• Examples were added / adjusted (see examples/ directory)
• Unit tests got implemented or updated
• Unit tests are passing: make test (will be checked by CI)
• No linter issues: make lint (will be checked by CI)