Improve Tramp file name completion

Improve Tramp file name completion

This fixes Bug#51386, Bug#52758, Bug#53513, Bug#54042 and Bug#60505.

* doc/misc/tramp.texi (File name completion): Remove completion
styles restrictions.

* lisp/minibuffer.el (completion-styles): Fix docstring.

* lisp/net/tramp.el (tramp-methods) <->: Add.
(tramp-completion-file-name-handler-alist):
Add `expand-file-name', `file-exists-p', `file-name-directory' and
`file-name-nondirectory'.
(tramp-dissect-file-name): Do not extra check for
`tramp-default-method-marker'.
(tramp-completion-handle-expand-file-name)
(tramp-completion-handle-file-exists-p)
(tramp-completion-handle-file-name-directory)
(tramp-completion-handle-file-name-nondirectory): New defuns.
(tramp-completion-handle-file-name-all-completions): Remove duplicates.

* test/lisp/net/tramp-tests.el
(tramp-test26-interactive-file-name-completion): New test.