Most operations emit signals before all updates have been performed to the document

[peitschie]

As highlighted in #827, many operations in WebODF core start emitting signals before the operation has completed execution. Some do this directly, but other secondary functions on OdtDocument (e.g., fixCursorPositions, moveCursor) quietly emit signals when executed.

This is quite undesirable as consumers of the signals may find the document or cursors are in invalid states (e.g., #824 was caused by the stepInserted signal being emitted while the cursor was in an invalid position).