Implement gitlab CI/CD pipeline that invokes entire BuildStream REST API flow E2E

[Rajeshkumar-s2]

Description of the Solution

Replaces the minimal stub CI/CD pipeline with a complete 12-stage GitLab pipeline that invokes the BuildStream REST API end-to-end, from authentication through image validation. Also fixes a 500 error in the build-image API for x86_64 architectures.

• - 12-stage sequential workflow: auth → create-job → parse-catalog → generate-input-files → create-local-repo → poll-local-repo → get-roles → build-images → poll-build-status → validate-image → poll-validate-status → job-summary
• - Secure TLS handling: Consumes BSM_API_CERT CI/CD variable (supports both File-type and regular variables), validates PEM structure and certificate syntax with openssl x509, replaces all curl -k with --cacert
• - GitLab API TLS: Uses --cacert ${CI_SERVER_TLS_CA_FILE} for GitLab API calls
• - One-time OAuth registration: Registers client credentials on first run, persists BSM_CLIENT_ID/BSM_CLIENT_SECRET as masked GitLab CI/CD variables for subsequent runs
• - Job traceability: Updates GitLab pipeline description with BSM Job ID; all stage headers prefixed with [${JOB_ID}]
• - Async stage polling: Polls long-running stages (local-repo, build-image, validate-image) with configurable interval and max attempts
• - Job summary: Final stage fetches job status and prints a formatted table of all stage results with error details

Testing

https://100.10.0.112/root/omnia-catalog/-/pipelines/22

Suggested Reviewers

If you wish to suggest specific reviewers for this solution, please include them in this section. Be sure to include the @ before the GitHub username.
@priti-parate @Venu-p1 @abhishek-sa1 @Kratika-P