Split the JUnit 5 `OutputCapture` class into separate `OutputExtension`
and `CapturedOutput` classes. The JUnit 5 callback methods are now
contained only in the `OutputExtension` class so no longer pollute the
public API that users will interact with.
The `CapturedOutput` class has also been updated to capture System.err
and System.out separately to allow distinct assertions if required.
Closes gh-17029
Update endpoint code to provide cleaner separation of concerns.
Specifically, the top level endpoint package is no longer aware of
the fact that JMX and HTTP are ultimately used to expose endpoints.
Caching concerns have also been abstracted behind a general purpose
`OperationMethodInvokerAdvisor` interface.
Configuration properties have been refined to further enforce
separation. The `management.endpoint.<name>` prefix provides
configuration for a single endpoint (including enable and cache
time-to-live). These properties are now technology agnostic (they
don't include `web` or `jmx` sub properties).
The `management.endpoints.<technology>` prefix provide exposure specific
configuration. For example, `management.endpoints.web.path-mapping`
allow endpoint URLs to be changed.
Endpoint enabled/disabled logic has been simplified so that endpoints
can't be disabled per exposure technology. Instead a filter based
approach is used to allow refinement of what endpoints are exposed over
a given technology.
Fixes gh-10176