Closes gh-21351

Closes gh-21342

Closes gh-21348

Closes gh-21346

Closes gh-21213

Prior to this commit, the property was a Boolean with a null default.
If it was explicitly set by the user, a context customizer would use
that value to set it on the context. However, if it was not set, the default
wouldn't be tomcat's default but `false` because it was explicitly set to
`false` in `TomcatServletWebServerFactory`. This commit defaults the property
itself to `false` so that the default is more obvious to the user.

Fixes gh-20796

Fixes gh-20759

Closes gh-21340

Closes gh-21339

Closes gh-21338

Closes gh-21337

Closes gh-21336

Closes gh-21335

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