Fix forced snap status being removed when changing transform mode

The `SNAP_FORCED` setting is set to the operation and not the snap
status.

Therefore, this option should not be cleared along with the other
statuses when resetting snapping.

Move then the location of this setting to `TransInfo::modifiers`.

source/blender/editors/transform/transform.c

@@ -1589,7 +1589,7 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
     /* Update `ToolSettings` for properties that change during modal. */
     if (t->flag & T_MODAL) {
       /* Do we check for parameter? */
-      if (transformModeUseSnap(t) && !(t->tsnap.status & SNAP_FORCED)) {
+      if (transformModeUseSnap(t) && !(t->modifiers & MOD_SNAP_FORCED)) {
         if (!(t->modifiers & MOD_SNAP) != !(t->tsnap.flag & SCE_SNAP)) {
           /* Type is #eSnapFlag, but type must match various snap attributes in #ToolSettings. */
           short *snap_flag_ptr;