api: add API for themes

co-author: hlpr98 <hlpr98@gmail.com> (dict2hlattrs function)

orange is sus??

NOVEMBER DAWN

erase the lie that is redraw_later()

src/nvim/cursor.c

@@ -482,7 +482,7 @@ bool leftcol_changed(void)
 
   if (retval)
     curwin->w_set_curswant = true;
-  redraw_later(NOT_VALID);
+  redraw_later(curwin, NOT_VALID);
   return retval;
 }