patch 9.1.1461: tabpanel: tabpanel vanishes with popup menu

patch 9.1.1461: tabpanel: tabpanel vanishes with popup menu

Problem:  tabpanel: tabpanel vanishes with popup menu
Solution: remove pum-related test in tabpanel_leftcol(), refactor a few
          related functions (Hirohito Higashi)

This commit does the following:
- Delete unnecessary pum-related checks in the tabpanel_leftcol()
  function
- remove pum-related check in tabpanel_leftcol()
- The argument of the TPL_LCOL() macro has been deleted.
- The argument of the tabpanel_leftcol() function has been changed
  to void
- The return type of the `win_comp_pos()` function has been changed to
  void

closes: #17549

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>