[DataGrid] Add new CSV export option: getRowsToExport

[flaviendelangle]

• Docs
• Tests

Closes #3610

• Export the collapsed groups by default on the CSV export (if you feel it's better to do a one-liner standalone PR for this change I can)
• Add a new getRowsToExport method to GridCsvExportOptions
• Add a test
• Add doc examples with and without row grouping

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	166.9	383.2	255.4	264.22	84.035
Sort 100k rows	ms	301.2	674.5	661.7	588.14	143.898
Select 100k rows	ms	158.1	309.3	188.5	209.66	53.139
Deselect 100k rows	ms	118.5	290	183.8	179.56	62.661

Generated by 🚫 dangerJS against 78392b3

[flaviendelangle]

@cherniavskii #3736 being merged, I updated the behavior to export the collapsed rows.
The doc examples and the default behaviors should not be consistent.

I'm adding @joserodolfofreitas for the doc part

[flaviendelangle]

I'm only passing the apiRef since most of the time users will want to use a selector, and selectors should be given the apiRef instead of the state whenever possible after #3663.

Not sure if we want to pass anything else.
We could pass a callback to generate them (like getDefaultRowsToExport), but the behavior is so simple right now that I'm not sure it would be very useful.

Anyway, I let the params as an object to be able to add things later.

[joserodolfofreitas]

I like how powerful the getRowsToExport method is. But I'm not sure we should use it to address the export without groups from row grouping.

I'd leave the current example for now, but replace it soon with an easier way to handle this case. Something like "disableRowGrouping". What do you think?
I'll then open a new issue for it.

[joserodolfofreitas]

It's looking great!
Just one more point about the default exported rows.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.