Closes gh-21334

Closes gh-21333

Closes gh-21332

Closes gh-21331

Closes gh-21330

Previously, unlike embedded Jetty, Netty, and Tomcat, Undertow would
not stop when one of its worker threads was in use. This meant that a
a long-running or stalled request could prevent the application from
shutting down in response to SIGTERM or SIGINT, and SIGTERM would be
required to get the process to exit.

This commit updates the factories for the reactive and servlet
Undertow web server factories to configure Undertow to use a 0ms
shutdown timeout. This aligns it with the behaviour of Jetty, Netty,
and Tomcat. Tests have been introduced to verify the behaviour across
the reactive and servlet variants of all four supported embedded web
servers.

Fixes gh-21319

Fixes gh-17001

Closes gh-21320

Update `StaticResourceJars` to catch both `IOException` and
`InvalidPathException` when checking URLs. Prior to this commit only
`IOException` was caught which worked on Java 8 but not Java 11 or
above.

Fixes gh-21312

Closes gh-21260

See gh-21265

Closes gh-21262

Closes gh-21265

Update `ValueObjectBinder` reattempt conversion if the `@DefaultValue`
contains a single element. Prior to this commit, single element
conversion relied on the `ArrayToObjectConverter` which isn't always
available.

Fixes gh-21264

Closes gh-20950

Closes gh-20941

Closes gh-20952

Closes gh-20946

Closes gh-20988

Closes gh-20939

Closes gh-21195

Closes gh-20948

Closes gh-21209

Closes gh-20940

Closes gh-20940

Closes gh-20938

This commit upgrades to RSocket 1.0.0-RC7.
This new RC brings API changes we have to adapt to. As of this commit,
we're introducing a new `RSocketServerCustomizer` which replaces the now
deprecated `ServerRSocketFactoryProcessor`.

Closes gh-21046

Closes gh-21205

Closes gh-21204

Closes gh-21203

Closes gh-21202

Closes gh-21201

Closes gh-21200

Closes gh-21199

Closes gh-21198

Closes gh-21197