patch 8.2.4339: CTRL-A does not work properly with the cmdline popup menu

Problem:    CTRL-A does not work properly with the cmdline popup menu.
Solution:   Fix issues with CTRL-A.  Add more tests for the cmdline popup
            menu.  Remove TermWait() before VeriryScreenDump().  Refactor the
            cmdline popup code. (Yegappan Lakshmanan, closes #9735)
diff --git a/src/popupmenu.c b/src/popupmenu.c
index cf2f2ef..18f2480 100644
--- a/src/popupmenu.c
+++ b/src/popupmenu.c
@@ -117,6 +117,7 @@
 	// can decide when to reposition the popup menu.
 	pum_window = curwin;
 	if (State == CMDLINE)
+	    // cmdline completion popup menu
 	    pum_win_row = cmdline_row;
 	else
 	    pum_win_row = curwin->w_wrow + W_WINROW(curwin);
@@ -220,6 +221,7 @@
 	// Calculate column
 #ifdef FEAT_WILDMENU
 	if (State == CMDLINE)
+	    // cmdline completion popup menu
 	    cursor_col = cmdline_compl_startcol();
 	else
 #endif