Closes gh-13534

* pr/13534:
  Polish

See gh-13534

See gh-13534

Closes gh-12742

Previously, when a user had declared a custom MultipartResolver bean
that is a CommonsMultipartResolver, part resolution would fail. The
failure was occurring as the servlet container was consuming the parts
before CommonsMultipartResolver had a chance to read them. This was
happening because a MultipartConfigElement was being auto-configured.

This commit updates the multipart auto-configuration so that a
MultipartConfigElement is not auto-configured when there is a
CommonsMultipartResolver bean in the context.

Closes gh-7735

Closes gh-13450

Closes gh-13521

Closes gh-13529

This commit makes sure that JMS and Mail JNDI lookups behave the same
way as DataSource JNDI lookups by enabling the "resourceRef" flag.

This will make sure to add "java:comp/env" to the lookup if the JNDI
name doesn't already contain it. If that name does not exist, a second
attempt to the original name will be issued automatically.

Closes gh-12803

Closes gh-13525

Closes gh-13526

Closes gh-12161

Previously, Slf4jLoggingSystem would install SLF4JBridgeHandler into
JUL but would only remove a single root handler that was a
ConsoleHandler. If there were was than one root handler or the single
root handler was of a different type, they would not be uninstalled.
When deploying an application to Tomcat, this led to duplicate log
messages appearing in Tomcat’s console output and to logging from
other application or Tomcat itself being routed into an
application-specific log file enabled using the logging.file
configuration property.

A secondary, related problem was that LogbackLoggingSystem installs a
LevelChangePropagator so that Logback’s log level configuration is
propagated into JUL. This meant that an individual Boot app with
custom log level configuration could change the log levels of Tomcat
itself and of any other applications that had been deployed to Tomcat
and use JUL.

This commit updates both Slf4jLoggingSystem and LogbackLoggingSystem
so that they only change JUL’s configuration if it hasn’t already been
customized. The configuration is deemed to have not been customised if
there’s a single root handler and its a console handler.

Closes gh-13470

Since SPR-16898, `HttpStatus.toString()` has changed and we should
instead rely on `HttpStatus.value()` to get the HTTP status number.

This commit adds support for CachingConnectionFactory for both Artemis
and ActiveMQ. If connection pooling is not enabled explicitly, sessions,
producers and consumers are cached. The factory can be further
customized, including reverting to the raw ConnectionFactory, using the
`spring.jms.*` namespace.

Closes gh-12161

This commit expands ActiveMQ's connection pooling to artemis. The same
pooling features are now shared by the two brokers and a
PooledConnectionFactory can be auto-configured when the necessary jar is
present.

Closes gh-13523

Since SPR-16898, `HttpStatus.toString()` has changed and we should
instead rely on `HttpStatus.value()` to get the HTTP status number.