Initial Migration to GCP CI/CD

[rpl-ffl]

• Jenkinsfile are introduced for both manual CI and PR scans
• Merged submodule path+content update so buildbot can now pull latest sonic
• Gofmt check is now enabled on Jenkins
• Removed obsolete github actions from repo

[rpl-ffl]

Pending reconfiguration of GCP image - to fix 'gofmt not found' bug during check norma format step.