refactor: fix clang-tidy warnings

Enable and fix bugprone-misplaced-widening-cast warning.

Fix some modernize-macro-to-enum and readability-else-after-return
warnings, but don't enable them. While the warnings can be useful, they
are in general too noisy to enable.

src/nvim/normal.c

@@ -4299,9 +4299,8 @@ static void nv_brackets(cmdarg_T *cap)
                         cap->nchar == 's', false, NULL) == 0) {
         clearopbeep(cap->oap);
         break;
-      } else {
-        curwin->w_set_curswant = true;
       }
+      curwin->w_set_curswant = true;
     }
     if (cap->oap->op_type == OP_NOP && (fdo_flags & FDO_SEARCH) && KeyTyped) {
       foldOpenCursor();