Add live updates support to Grid

[bmblb]

In the related issue https://github.com/bryntum/support/issues/6226 we introduced two concepts which are helpful in collaboration, one for UI and two for the data level:

1. Queue - feature to run functions uninterrupted
2. Revisions - feature to track user changes and order them
3. Transactional features - way to block queue of incoming changes when user is working with the view

Revisions are mostly used to resolve conflicts that occur in a Gantt chart. Although they could be useful in the grid too, there are different strategies and frameworks that allow more flexibility. Implementing revisions support is not entirely necessary, but nice to have.

However, queue and transactional features are required on the Grid level to help handle the UI in presence of the incoming changes. At the same time, we should be flexible to not put constraints on the means of communication among clients. As with Gantt, we should only make client part to emit changes, accept changes and separate user workflow from the incoming changes.