NUX: Avoid popover refresh on tip mount

[aduth]

Closes #6956

This pull request seeks to resolve an issue where end-to-end tests frequently fail due to DotTip mount behavior to refresh its popover positioning. This was meant to be resolved in #7544 and #7493, yet persists. I suspect the bug is due to the fact that isVisible changes between the time the setTimeout is scheduled and when the callback is reached. The approach here intends to remove the setTimeout altogether, resolving the original issue with positioning by ensuring that the post title is rendered immediately. This requires that we change the default behavior of PostTypeSupportCheck to assume true if the post type is not yet known. I expect that this is probably the majority case anyways. This may also become a non-issue anyways once #7546 is merged, as the post type data is immediately available, but due to the behavior of resolvers being asynchronous, it doesn't take effect during the initial render.

Testing instructions:

1. Clear local storage
   • Type localStorage.clear() in browser console.
2. Refresh the editor page
3. Note that the DotTip is positioned correctly

Ensure end-to-end tests pass:

npm run test-e2e

Ensure unit tests pass:

npm run test-unit

[noisysocks]

Sounds like a good compromise. Code LGTM—thanks for adding docs and tests!