Add Tramp sudoedit method

Add Tramp sudoedit method

* doc/misc/tramp.texi (Quick Start Guide): New section "Using sudoedit".
(External methods) <sudoedit>: Describe.

* lisp/net/tramp-adb.el (tramp-adb-file-name-handler-alist):
* lisp/net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist):
* lisp/net/tramp-rclone.el (tramp-rclone-file-name-handler-alist):
* lisp/net/tramp-sh.el (tramp-sh-file-name-handler-alist)
* lisp/net/tramp-smb.el (tramp-smb-file-name-handler-alist):
Add handler.

* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-uid-gid): Rename from
`tramp-sh-handle-set-file-uid-gid'.  Handle only remote file names.

* lisp/net/tramp-sudoedit.el: New file.

* lisp/net/tramp.el (tramp-file-name-for-operation): Handle also
`tramp-set-file-uid-gid'.
(tramp-set-file-uid-gid): New defun.
(tramp-get-local-uid, tramp-get-local-gid): Cache result.

* test/lisp/net/tramp-tests.el (tramp--test-sudoedit-p): New defun.
(tramp-test20-file-modes, tramp-test22-file-times)
(tramp--test-sudoedit-p): Use it.