portablectl: add --now and --enable to attach/detach

Add shortcuts to enable and start, or disable and stop, portable
services with a single portablectl command.
Allow to pass a filter on detach, as it's necessary to call
GetImageMetadata to get the unit names associated with an image.

Fixes #10232

shell-completion/bash/portablectl

@@ -34,7 +34,7 @@ _portablectl() {
     local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
     local -A OPTS=(
         [STANDALONE]='-q --quiet --runtime --no-reload --cat --no-pager --no-legend
-                              --no-ask-password -h --help --version'
+                              --no-ask-password --enable --now -h --help --version'
         [ARG]='-p --profile --copy -H --host -M --machine'
     )