Add delay since on grid rendered column have not init yet, hence filt…

[MayaKirova]

…ers are not fully populated correctly.

Closes #1147

Would be even better if we finally merge the ready event: IgniteUI/igniteui-angular#15226
So we won't need workarounds.

[MarielaTihova]

@MayaKirova this doesn't seem to resolve the issue for me in the State persistence sample. Does it do the trick on your machine? If so, maybe a delay of 1 second is not enough? 🤔 💭

[MayaKirova]

@MarielaTihova It did resolve it for me, but it could be flaky. I've added an await for the grid data changed that should suffice. Please test it on your side.