fix issue #5814. onValueChange not triggered when selecting text from right to left

[virgil1996]

onValueChange not triggered when selecting text from right to left

✅ Closes: #5814

Description
when selecting text from right to left, it will trigger set_selection, remove_text, insert_text at the same time, cause onValueChange not trigger.

Issue
Fixes: (link to issue)

Example

[changeset-bot]

🦋 Changeset detected

Latest commit: 42bb61b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
slate	Patch

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[dylans]

@virgil1996 this looks reasonable. Could you please add a changeset as a patch and I'll land this.

[virgil1996]

@virgil1996 this looks reasonable. Could you please add a changeset as a patch and I'll land this.

done.

[nabbydude]

With how the flushing flag is separated, this will trigger onChange twice in one frame, so any generic behavior will trigger twice. (the second will also be called while editor.operations is empty)

seems like strange behavior to have in core slate--since onValueChange and onSelectionChange are slate-react specific concepts.

I think it would make more sense if the slate-react onChange handler could see all the operations in a frame and decide to run one or both of the sub-events with one call.