OSDOCS-4352: Updated cluster-wide proxy documentation

[EricPonvelle]

Version(s): Enterprise-4.11+

Issue: OSDOCS-4352

Link to docs preview:

• OCP
  • Original
  • Revised
• ROSA
• Dedicated

QE review:

• [ ] QE has approved this change.

Additional information: Combined the OCP cluster-wide proxy documentation with the OSD/ROSA documentation to make it easier to maintain all three sets.

[ocpdocs-previewbot]

🤖 Updated build preview is available at: https://51726--docspreview.netlify.app

Build log: https://circleci.com/gh/ocpdocs-previewbot/openshift-docs/3340

[EricPonvelle]

/cherrypick enterprise-4.11

[EricPonvelle]

/cherrypick enterprise-4.12

[EricPonvelle]

/cherrypick enterprise-4.11

[openshift-cherrypick-robot]

@EricPonvelle: new pull request created: #52674

In response to this:

/cherrypick enterprise-4.11

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[EricPonvelle]

/cherrypick enterprise-4.12

[openshift-cherrypick-robot]

@EricPonvelle: new pull request created: #52681

In response to this:

/cherrypick enterprise-4.12

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.