storage controller: grant 'admin' access to all APIs

[jcsp]

Problem

Currently, using storcon-cli requires user to select a token with either pageserverapi or admin scope depending on which endpoint they're using.

Summary of changes

• In check_permissions, permit access with the admin scope even if the required scope is missing. The effect is that an endpoint that required pageserverapi now accepts either pageserverapi or admin, and for the CLI one can simply use an admin scope token for everything.

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

2748 tests run: 2624 passed, 0 failed, 124 skipped (full report)

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Code coverage* (full report)

• functions: 27.9% (6381 of 22848 functions)
• lines: 46.8% (44981 of 96053 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
2434a6a at 2024-04-04T11:38:04.660Z :recycle:}