Add notices for active and repeated rate limiting

[daledupreez]

Fixes STRIPE-<linear_issue_id>
Fixes #<github_issue_id>

Changes proposed in this Pull Request:

This PR builds on #4327 and adds notices based on the data that we're tracking for rate limiting. In particular, it shows a notice for the following cases:

• When API calls are currently rate limited
• When there have been 3 or more periods of rate limiting in the last hour
• When there have been 5 or more periods of rate limiting in the last 24 hours

None of the notices are dismissible. It may make more sense for the repeated ones to be dismissible, especially the 24 hour one, as users may resolve the issue.

There are still some outstanding issues:

• The wording and CTA for the notices is very much a first draft -- what should we ask users to do if their site is being rate limited?
• I picked the timing for these options without thinking about it too much. We should consider what they look like.
• Should we include the repeated notices in this first pass?
• Should we also trigger emails when we trigger rate limiting? This feels like it should be a future improvement.

Testing instructions

---

• Covered with tests (or have a good reason not to test in description ☝️)
• Tested on mobile (or does not apply)

Changelog entry

• This Pull Request does not require a changelog entry. (Comment required below)

Changelog Entry Comment

Comment

Post merge

• Added testing instructions to the Release Testing Instructions wiki page (or does not apply)
• Added the needs docs label (or does not apply)
• Included this PR in the Release Thread scope (or does not apply)