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

Closes gh-21196

Closes gh-21194

Closes gh-21193

Closes gh-21192

Closes gh-21191

Closes gh-21190

Closes gh-21189

Closes gh-21188

Closes gh-21187

Closes gh-21186

Closes gh-21185

Closes gh-21184

Closes gh-21183

Closes gh-21182

Closes gh-21181

Closes gh-21180

Closes gh-21179

Update `JarFile` so that `super.close()` is called early so that the
file is not left open. Since we re-implement `JarFile` methods to work
directly on the underlying `RandomAccessDataFile`, it should be safe
to close immediately.

Closes gh-21177

Closes gh-21174

Update `ConfigFileApplicationListener` to throw a better exception if
`classpath*:` is used as a location.

Closes gh-21168

Closes gh-20942

Clsoes gh-20937