Blender Git Loki

Fix T78392: [2.83.5, 2.90, 2.91] Crash on undo/ redo after changing modes.

During undo/redo read code is expected to clear the `OB_MODE_EDIT`
bitflag of `Object.mode`, for some reasons.

This was not done anymore for re-used Objects, we need to add a special
handling case for that too.

Should be backported to 2.90 and 2.83 (will probably not be straight
forward for the latter).