fdo#77944: No need to store updated formulas in undo document when moving.

This causes crash with dbgutil build, and I'm sure would cause issues with the
release build as well.

We now use broadcasting to handle reference update during undo of block move,
so this old way of handling undo for block move is redundant and obviously
causes issues.

Change-Id: I9dcbb9d9e3808da3f8510eab16ad21b626f881d9