[DataGrid] Fix dimensions computation with autoHeight and scroll x

[flaviendelangle]

Fixes #5398

The problem was that when props.autoHeight = true, viewportOuterSize.height === content.height
If there is a scrollbar for the X axis, then the viewportOuterSize.height can't fit the content AND the scrollbar for the X axis.
So the dimensions script thinks he must put a scrollbar for the Y axis (which will never be rendered since #5164)

As a consequence, the pinned columns think they must offset by the width of the scroll bar in the Y axis even if it's not needed.

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My solution is first to make sure that there is never a scrollar for the Y axis in the rooter dimensions when props.autoHeight = true.
And then to fix the viewportOuterSize.height to take the scrollbar for the X axis into account if any.

Codesandbox of #5398 with the fix

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	264.5	465.4	363.4	348.8	71.139
Sort 100k rows	ms	462.9	834	696.1	678.36	119.932
Select 100k rows	ms	130.2	187.7	149.2	156.88	24.339
Deselect 100k rows	ms	101.1	221.1	204.2	170.6	49.766

Generated by 🚫 dangerJS against 2f99cb1

[flaviendelangle]

I split the logic in two because we started to have a lot of conditions with autoHeight inside the logic, making it harder to read.

When autoHeight is on, the logic is very simple since we only have to care about one direction.

[cherniavskii]

Looks great!