Make Eglot consider FileSystemWatcher.kind when watching files

Make Eglot consider FileSystemWatcher.kind when watching files

bug#58677

* eglot.el (eglot-register-capability
  workspace/didChangeWatchedFiles): Rework

Only send notifications of interest, as determined by the optional LSP
FileSystemWatcher.kind bitmask provided by the server.

When the FileSystemWatcher.kind property is omitted, use the default
value of 7, which is computed from taking the bitwise OR operation
WatchKind.Create (1) | WatchKind.Change (2) | WatchKind.Delete (4).