Fix caching issues in `ApplicationContextRequestMatcher` and allow
subclasses to ignore an application context entirely. Update existing
matcher implementations so that they deal with the management context
correctly.

Prior to this commit, the `ApplicationContextRequestMatcher` would
return a context cached from the first request. It also didn't
provide any way to ignore a context. This meant that if the user was
running the management server on a different port the matching results
could be inconsistent depending on if the first request arrived on
the regular context or the management context. It also meant that we
could not distinguish between the regular context and the management
context when matching.

Closes gh-18012