Add TLS support for CTLog server

[fghanmi]

Summary

This pull request introduces support for enabling TLS security for CTLog. By adding two new command-line flags--tls_certificate and --tls_key which represents the path to server TLS certificate and private key respectively.
And also implementing the necessary logic to handle TLS, this update enhances the security of CTLog.

Release Note

• Feature: Added support for TLS security for CTLog server.
  New Flags: --tls_certificate and --tls_key to specify the file path for service certificate and private key.
  Behavior: If --tls_certificate and --tls_key flags are not both provided, the system will default to insecure connections.
  Security: This update significantly enhances the security of data in transit by enabling TLS.

Resolves Issue: #1522

Checklist

• I have updated the CHANGELOG.
  • Adjust the draft version number according to semantic versioning rules.
• I have updated documentation accordingly.

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[fghanmi]

Hello,
It seems that "Missing permissions: cloudbuild.builds.get" prevents the build from starting/succeeding.
Could you please help ?
Thanks!

[mhutchinson]

/gcbrun

[mhutchinson]

/gcbrun

[mhutchinson]

Hey @fghanmi one tip to make incremental github reviews easier for the reviewer: once a commit has been proposed, make any further changes as commits on top of that instead of squashing the commits together and force pushing. This makes it easier to see that recent changes have not affected code that a reviewer may already have looked at. The commits can all be squashed together at the point where the PR is merged into the main branch.