Added support for server side row model to enable server side row grouping, similar to infinite row model

[anujdhillxn]

No description provided.

[anujdhillxn]

Fixes #410

[gvwilson]

Thanks for the PR @anujdhillxn - please edit the description to give us an idea of what problem this solves and how you've gone about tackling it so that I can find a reviewer.

[anujdhillxn]

Hi @gvwilson. Thanks for the response. I have edited the PR title and the attached issue to be more descriptive.

[BSd3v]

@anujdhillxn,

I am open to this, however, can you provide some more types of tests.

For example, we need to have grouping (this is what you have), filters and sorting, just like how we have it in the infinite model.

We had initially avoided this due to complexity and the logic behind setting it up, also had issues with creating the payload to the dash server for the necessary details.

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Also, there is a way to setup the endpoint that has been documented:
https://community.plotly.com/t/serverside-rowmodeltype-with-storing-changes/82787/10?u=jinnyzor

This example demonstrates how to set it up for the grid, my concern with just having the request that you might lose data that is beneficial to the query.