vim-patch:9.1.0186: cursor pos wrong on mouse click after eol with 'rl', 've' and conceal (#27903)

Problem:  Wrong cursor position when clicking after end of line with
          'rightleft', 'virtualedit' and conceal.
Solution: Set values in ScreenCols[] also with SLF_RIGHTLEFT.  Also fix
          off-by-one cursor position with 'colorcolumn' (zeertzjq).

closes: vim/vim#14218

deb2204bff

src/nvim/grid_defs.h

@@ -37,7 +37,7 @@ enum {
 /// attrs[] contains the highlighting attribute for each cell.
 ///
 /// vcols[] contains the virtual columns in the line. -1 means not available
-/// or before buffer text, MAXCOL means after the end of the line.
+/// or before buffer text.
 /// -2 or -3 means in fold column and a mouse click should:
 ///  -2: open a fold
 ///  -3: close a fold