Closes gh-13420

Closes gh-13412

Fixes gh-12872

Fixes gh-12987

Closes gh-13411

Closes gh-13401

* rstoyanchev-13315:
  Follow-up dates for web server config documentation

See gh-13315

Closes gh-13368

Update the duplicate-finder-maven-plugin configuration to ignore
module-info classes.

Closes gh-13403

Fixes gh-828

* pr/13344:
  Polish "Fix caching issues with map property sources"
  Fix caching issues with map property sources

Refine the property source cache key fix so that a copy of the
key is only taken when the values change. This allows us to
retain the previous performance optimization of not creating
unnecessary string arrays.

Closes gh-13344

Update `SpringIterableConfigurationPropertySource` so that the cache
key from a `MapPropertySource` is invalidated when the map contents
changes.

Prior to this commit, the actual keys of the map were used as the key.
This meant that if the underlying map changed, they key wouldn't be
invalidated because it ultimately pointed to the same object instance.

See gh-13344

Closes gh-13360

Fixes gh-13399

This commit regroups the documentation on how to configure a web server
in Spring Boot. The same concepts apply, whether the server is
Tomcat/Netty/Jetty/Undertow, or if it's deployed for a Servlet or
Reactive web application.

Closes gh-13315

Prior to this commit, the `DefaultErrorWebExceptionHandler` would parse
the HTTP "Accept" headers when routing the request to the error handler;
if an error occured during parsing, an `InvalidMediaTypeException` would
be thrown and break the error handling for this request.

This commit ignores those exceptions and makes sure that the error
handling function does not override the response status or the error
itself with those exceptions.

Closes: gh-13372

Closes gh-1327

Closes gh-13397

Closes gh-13396

Closes gh-13395

Closes gh-13394

Closes gh-13393

Closes gh-13392

Closes gh-13391