Consider buffer-local context+namespace in all display commands

Consider buffer-local context+namespace in all display commands

* kubed-transient.el (kubed-transient-infix): Remove.
(kubed-transient-read-context): New function.
(kubed-transient-read-namespace): Take into account value of
"--context=" infix argument.
(kubed-transient-display): Add "--context=" infix argument.
* kubed.el (kubed-display-resource): Update interactive spec.
(kubed--static-if): Simplify empty "else" parts.
(kubed-define-resource): Update interactive spec for
generated 'kubed-display-RESOURCE' commands.
(kubed-local-context, kubed-local-namespace)
(kubed-local-context-and-namespace): New functions.