hotfix: block grid live editing race condition

[nielslyngsoe]

Makes Block Grid Editor only set its data if its not in Live Editing Mode. Cause otherwise they end up competing with each other and eventually out rule the corrections made by the Property Editor.

Fixes: umbraco/Umbraco-CMS#16227

Here a semantic diff for better overview:
https://app.semanticdiff.com/gh/umbraco/Umbraco.CMS.Backoffice/pull/2101/changes#src/packages/block/block/workspace/block-workspace.context.ts

Types of changes

This makes sure the Block Workspace observes data of the Property Editor while in create-state, in this way the corrections made of the Property Editor, like rowSpan setting, gets set and the Block Workspace receives that correction.

Only sets the Blocks data if its not in live editing mode. Cause setting these will eventually overwrite the corrections from the Property Editor.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (minor updates related to the tooling or maintenance of the repository, does not impact compiled assets)

Motivation and context

How to test?

Screenshots (if appropriate)

Checklist

• If my change requires a change to the documentation, I have updated the documentation in this pull request.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[iOvergaard]

I was able to reproduce the problem before applying this fix, and after changing to this branch and re-creating the block grid in the exact same way, I was no longer able to reproduce the bug! LGTM!