This commit improves the `health` endpoint to run health check for a
particular component or, if that component is itself a composite, an
instance of that component.

Concretely, it is now possible to issue a `GET` on
`/actuator/health/{component}` and
`/actuator/health/{component}/instance` to retrieve the health of a
component or an instance of a composite component, respectively.

If details cannot be showed for the current user, any request leads to a
404 and does not invoke the health check at all.

Closes gh-8865

Closes gh-13169

Prior to 3db5c70b, RelaxedDataBinder would use a ConversionService
to convert a String into a File via its ObjectToObjectConverter.
3db5c70b changed the configuration of the data binder such that a
FileEditor was registered. Property editors take precedence over any
conversion service so the FileEditor was used instead. This caused a
regression as the FileEditor uses slightly unusual logic for a String
to File conversion. Specifically, when given a value of ".", it will
locate a ClassPathResource for the root of the classpath and use the
result of calling getFile() on that resource. This fails when the
root of the classpath is in a jar file and also provides a different
result when the root of the classpath is not the current directory.

This commit updates RelaxedDataBinder to suppress the registration
of an editor for File. This restores the behaviour prior to 3db5c70b
by allowing the ConversionService to be used instead.

Closes gh-12786

Closes gh-13195

See gh-13196

This commit updates the initial proposal to add support for reactive
use cases as well. A reactive application can use
ReactiveHealthIndicatorRegistry as an alternative to
HealthIndicatorRegistry.

Closes gh-4965

See gh-4965
Co-authored-by: Andy Wilkinson <awilkinson@pivotal.io>

This commit introduces HealthIndicatorRegistry which handles
registration of HealthIndicator instances. Registering new
HealthIndicator instances is now possible in runtime.

See gh-4965

* pr/13175:
  Polish "Respect lombok.AccessLevel attributes"
  Respect lombok.AccessLevel attributes

Closes gh-13175

Closes gh-13185

Closes gh-13185

See gh-13175

* pr/13174:
  Polish DefaultErrorWebExceptionHandler.renderErrorView()

Closes gh-13174

Closes gh-13182

Closes gh-13181

Closes gh-13178

Closes gh-13177

See gh-13169

Closes gh-13180

Closes gh-13179

* pr/13171:
  Remove @Deprecated on CouchbaseProperties.Endpoints.setKeyValue()

Closes gh-13171

* pr/11061:
  Polish "Allow repackage maven goal to take a source classifier"
  Allow repackage maven goal to take a source classifier

Closes gh-11061

Previously, the "classifier" attribute was only used to determine the
target classifier of the repackaged archive, always using the main
artifact as the source.

This commit changes the semantic of the attribute so that an existing
archive matching the "classifier" attribute can be used as source,
replacing the archive the same way the goal replaces the main archive
if no classifier is found.

If no artifact with the specified classifier exists, the repackaged
archive is still processed based on the main archive and attached to
the lifecycle using the value of the classifier attribute.

See gh-11061