[bugfix] Fix how selection works when selecting rows not yet inserted in the DOM

[gwak]

Because of how vertical-collection works, the TableRowMetaCache is only populated for a given row when inserted into the DOM, when vertical-collection invokes objectAt(index) function of tree node.
We thus need to setup non-existent meta cache from selected rows.

[tempo22]

I can confirm this fix this issue for me aswell

[sanmaverick]

I have tested these changes and they work well.

[ghost]

@gwak the package-lock.json changes here should be removed. Quick tip is to just git checkout master package-lock.json.

[ghost]

I've verified this fixes a bug in our application as well. Thank you @gwak !

[gwak]

@gwak the package-lock.json changes here should be removed. Quick tip is to just git checkout master package-lock.json.

@efx I've just removed the package-lock.json

[ghost]

@gwak are you able to update this PR with master and see what the error is? Once that is done we can try to get this merged into master.

[ghost]

Additionally, a unit or integration test should be included to assert the change.

[mixonic]

@gwak yeah I'm also very interested in learning how this manifests in usage.

[bantic]

This should be fixed by #727, which has been released in 2.0.0-beta.9.
@gwak When possible, can you try beta 9 and see if it fixes the issue for you?
I'm going to close this now as I believe #727 fully covers this, but please reopen if I'm mistaken.