refactor(grid): unused grid->line_wraps delenda est

This is not used as part of the logic to actually implement TUI line wrapping
In vim (especially gvim) it is used to emulate terminal-style text
selection. But in nvim we don't do that, and have no plans to reintroduce it.

src/nvim/ui_compositor.c

@@ -413,9 +413,7 @@ static void compose_line(Integer row, Integer startcol, Integer endcol, LineFlag
   assert(endcol <= chk_width);
   assert(row < chk_height);
 
-  if (!(grid && grid == &default_grid)) {
-    // TODO(bfredl): too conservative, need check
-    // grid->line_wraps if grid->Width == Width
+  if (!(grid && (grid == &default_grid || (grid->comp_col == 0 && grid->cols == Columns)))) {
     flags = flags & ~kLineFlagWrap;
   }