Add `toAdditionalPaths(...)` methods on the servlet and reactive
`EndpointRequest` classes to support matching of additional paths.
A new `AdditionalPathsMapper` interface provides the mappings between
endpoint IDs and any additional paths that they might use. The existing
`AutoConfiguredHealthEndpointGroups` class has been updated to implement
the interface.
Auto-configurations have also been updated so that additional health
endpoint paths (typically `/livez` and `/readyz`) are permitted
when using Spring Security without any custom configuration.
Fixes gh-40962