[w32handle] Remove use of w32handle for File, Console, Pipe and Socket (#5283)

* [w32file] Remove io_ops indirection

* [w32file] Replace use of w32handle by a GHashTable for File, Console and Pipe

* [Socket] Avoid relying on MonoIO.DuplicateHandle

* [w32socket] Remove force closing of sockets on shutdown

* fixup! [Socket] Avoid relying on MonoIO.DuplicateHandle

* [w32socket] Replace use of w32handle by a GHashTable

* [w32handle] Remove dead function mono_w32handle_new_fd

* fixup! [w32file] Replace use of w32handle by a GHashTable for File, Console and Pipe

* [w32handle] Remove dead variable mono_w32handle_fd_reserve

* [fdhandle] Factor w32file and w32socket common fdhandle code

* fixup! [Socket] Avoid relying on MonoIO.DuplicateHandle

* [w32socket] Fix GC safe/unsafe transitions

* fixup! [w32handle] Remove dead variable mono_w32handle_fd_reserve