* gnu/packages/lxqt.scm (lxqt-session)[arguments]: Add new phase to wrap
"lxqt-session" and add base paths for "lxqt" and "pcmanfm-qt" config folders
in system profile to "XDG_CONFIG_DIRS" environment variable.
Signed-off-by: Oleg Pykhalov <go.wigust@gmail.com>