Closes gh-10447

This commit extracts the configuration of MessageSourceAutoConfiguration
in a dedicated object.

Closes gh-9666

See gh-10456

Previously, StaticResourceJars would only find jars with
META-INF/resources content if it had been loaded by a URLClassLoader.
This is not the case on Java 9 and, as a result, static content in
META-INF/resources of any jars on the class path was not found.

This commit updates StaticResourceJars to fall back to using the
JVM's class path to find static resource jars when it was loaded by
a ClassLoader that is not a URLClassLoader.

Closes gh-10455

Previously, DevTools assumed that the TCCL was a URLClassLoader
when trying to determine the URLs that it should examine to determine
the locations that should be watched for triggering a restart. This
fails on Java 9 as the TCCL is not a URLClassLoader.

This commit updates the logic that determines the changeable URLs to
fall back to examining the JVM's class path when the TCCL is not a
URLClassLoader, typically because the application is running on Java
9. This fall back isn't a direct equivalent of the behaviour on Java 8
as the class path of the TCCL and the class path with which the JVM
was launched may not be the same. However, I consider the fix to be
reasonable for two reasons:

1. In reality, the class path of the TCCL and the class path with
   which the JVM was launched are the same.
2. There appears to be now to get the URLs on the class path of the
   TCCL on Java 9. There is a URLClassPath field, however Java 9's
   access restrictions prevent us from using it even if we resort to
   reflection.

Closes gh-10454

See gh-10454

Closes gh-10268

See gh-7226

See gh-10456

See gh-10455

See gh-10454

See gh-7226

See gh-10453

Closes gh-10430

Closes gh-10439

See gh-7226

Closes gh-10445

Simplify `AuthenticationManagerConfiguration` following the recent
Spring Security auto-configuration updates.

See gh-7958

Closes gh-10325

Liquibase does not currently work with Java 9. This commit disables on
test reproducing that behaviour when running with that version.

See gh-10442

See gh-7226

Closes gh-9530

The translations for the timezone names vary between Java 8 and Java
9. For example, with Java 9, UTC's name is no longer localized while
others have different localizations. This commit updates the test
to verify that the correct locale is being used while also tolerating
the different localization's of Java 8 and 9.

See gh-7226

Closes gh-10436

Closes gh-10435

See gh-10439

See gh-10328

See gh-10329

See gh-7053

See gh-10326