feat: existing scc instance support

[Soaib024]

Description

#140

Support for existing scc instance

Release required?

• No release
• Patch release (x.x.X)
• Minor release (x.X.x)
• Major release (X.x.x)

Release notes content

Run the pipeline

If the CI pipeline doesn't run when you create the PR, the PR requires a user with GitHub collaborators access to run the pipeline.

Run the CI pipeline when the PR is ready for review and you expect tests to pass. Add a comment to the PR with the following text:

/run pipeline

Checklist for reviewers

• If relevant, a test for the change is included or updated with this PR.
• If relevant, documentation for the change is included or updated with this PR.

For mergers

• Use a conventional commit message to set the release level. Follow the guidelines.
• Include information that users need to know about the PR in the commit message. The commit message becomes part of the GitHub release notes.
• Use the Squash and merge option.

[Soaib024]

/run pipeline

[Soaib024]

/run pipeline

[ocofaigh]

I would of thought this support should be added directly into https://github.com/terraform-ibm-modules/terraform-ibm-scc (and then exposed in the DA). That way we can support auth policy creation and attaching of an SCC Workload Protection instance to an existing SCC instance.

Also you need to ensure outputs support existing instance. For example you seem to be defaulting the value of the scc_crn to null when passing existing instance, when actually you should output the CRN of the existing instance.

[Soaib024]

Created a PR to support existing scc instance in module