Adapt Tramp's kubernetes integration

Adapt Tramp's kubernetes integration

* doc/misc/tramp.texi (Inline methods): Shorten kubernetes entry.
(Kubernetes setup): New node.
(Top, Configuration): Add it to the menu.

* lisp/net/tramp-container.el (tramp-kubernetes--context-namespace):
Adapt dpcstring.
(tramp-kubernetes-connection-local-default-profile)
(tramp-kubernetes-connection-local-default-variables)
(tramp-flatpak-connection-local-default-profile)
(tramp-flatpak-connection-local-default-variables): Rename.

* lisp/net/tramp.el (tramp-expand-args): Use `tramp-compat-take'.

* test/lisp/net/tramp-tests.el (tramp-test34-connection-local-variables)
(tramp-test34-explicit-shell-file-name): Don't let-bind
`connection-local-profile-alist' and `connection-local-criteria-alist'.