feat(code-references): prompt users to add required integrations

[afsuyadi]

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Changes

Contributes to #7436

1. Code References feature only show text "No code references found for this feature.", but doesn't inform the user what they should to next.
2. Add existing hooks to detect if GItHub or GitLab has been integrated
3. If the GitHub or GitLab has been integrated but no code references, it will just show "No code references found for this feature."
4. If the GitHub or GitLab has not been integrated, then it will show text with hyperlink to prompt user for integration.

How did you test this code?

1. Edit / Add a feature > go to usage tab
2. If no integration has been added, the text will prompt user to do it
3. if integration has been added but no code reference, the text will show "no code references"

After changes:
codereferences_integration_prompt - testing.webm

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