Previously, the documentation did not provide any guidance on using
Jersey alongside Spring MVC or any other web framework.

This improves the documentation in two ways:

1. It notes that, in the presence of both Jersey and Spring MVC, the
   Actuator will prefer Spring MVC for exposing HTTP endpoints.
2. It adds a how-to describing how to configure Jersey to forward
   requests for which it has no handler on to the rest of the filter
   chain. When Spring MVC is the other framework, this allows them to
   be handled by its dispatcher servlet.

Closes gh-17523