feat: Support OpenShift external IDP

[tolusha]

What does this PR do?

Support OpenShift external IDP

Screenshot/screencast of this PR

What issues does this PR fix or reference?

https://issues.redhat.com/browse/CRW-9763

How to test this PR?

eclipse-che/che-docs#3024

Common Test Scenarios

• Deploy Eclipse Che
• Start an empty workspace
• Open terminal and build/run an image
• Stop a workspace
• Check operator logs for reconciliation errors or infinite reconciliation loops
• Advanced authorization

PR Checklist

As the author of this Pull Request I made sure that:

• The Eclipse Contributor Agreement is valid
• Code produced is complete
• Code builds without errors
• Tests are covering the bugfix
• The repository devfile is up to date and works
• Relevant user documentation updated
• Relevant contributing documentation updated
• CI/CD changes implemented, documented and communicated

Reviewers

Reviewers, please comment how you tested the PR when approving it.

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: tolusha

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[ibuziuk]

Great job, but let's postpone the merge and have it in 7.116.0 for 3.28

[tolusha]

@rohanKanojia
I've addressed all remarks.

[openshift-ci]

PR needs rebase.

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