Allow other modules to change the node to update

Problem/Motivation

Other modules are unable to change which node gets updated; the first event dispatched is when the node to update (or newly created node) is already set. This is difficult if there are more complex rules about when to update which content like title / type matching.

Proposed resolution

Dispatch an event to allow setting this by other modules

Remaining tasks

Patch to be provided shortly

User interface changes

None

API changes

None

Data model changes

None

Release notes snippet

New event dispatched to allow other modules to change the node to update