Add pagination to credentials and project credentials page

[sharleenawinja]

Description

This PR adds pagination to the credentials, keychain credentials, and OAuth clients tables on the credentials list pages (10 items per page, with Previous/Next control). OAuth clients are now in a collapsible section, collapsed by default. Tables are ordered: credentials first, keychain credentials second, OAuth clients last.

Closes #4301

Validation steps

1. Go to /credentials with more than 10 credentials — confirm the table paginates

2. Confirm the OAuth Clients section is collapsed by default and the toggle shows/hides it.

3. If there are more than 10 OAuth clients, expand the section and confirm pagination works.

4. Verify the same behaviour on Project Settings → Credentials.

Additional notes for the reviewer

1. (Is there anything else the reviewer should know or look out for?)

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• I have performed an AI review of my code (we recommend using /review
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[sharleenawinja]

@midigofrank could you please review this PR when you have a moment? Thanks!