move.c: Fix move_to_output_directed problems

- Use workspace_show that correctly updates _NET_CURRENT_DESKTOP, warps
mouse.
- Use TAILQ_INSERT_TAIL only for focus_head. Focus order is not related
to direction.
- Call con_focus only if con was focused before. See testcase for
directional move with command criteria.
- Correct first call of move_to_output_directed in tree_move which
didn't call ipc_send_window_event("move", con) and
ewmh_update_wm_desktop().
- Don't produce events when the move doesn't happen. Correct
276-ipc-window-move.t as well.

testcases/t/276-ipc-window-move.t

@@ -34,7 +34,7 @@ sub move_subtest {
     is($move[0]->{container}->{window}, $window->{id}, 'window id matches');
 }
 
-subtest 'move right', \&move_subtest, 'move right';
+subtest 'move left', \&move_subtest, 'move left';
 subtest 'move to workspace', \&move_subtest, 'move to workspace ws_new';
 
 done_testing;