[bugfix] Reorder web view logic, other small fixes

[tsmethurst]

Description

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If this is a documentation change, please briefly describe what you've changed and why.

This pull request updates some of our web view status / account stuff:

• Reorder web view auth logic so that if an AP request comes in on a status URL, the AP representation can be served properly even if it's not a public status (assuming requester has permission to view it). Previously, we only served AP representations of public statuses that were requested using the URL rather than the AP URI, but this is not quite right.
• Serve 404 for local accounts that have been suspended, instead of showing a web view of an empty profile.
• Comment and tidy up for readability.

Checklist

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• I/we have read the GoToSocial contribution guidelines.
• I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
• I/we have performed a self-review of added code.
• I/we have written code that is legible and maintainable by others.
• I/we have commented the added code, particularly in hard-to-understand areas.
• I/we have made any necessary changes to documentation.
• I/we have added tests that cover new code.
• I/we have run tests and they pass locally with the changes.
• I/we have run go fmt ./... and golangci-lint run.

[huabin]

• Serve 404 for local accounts that have been suspended, instead of showing a web view of an empty profile.

It doesn't seem to work, it is still showing an empty profile.