[DataGrid] Fix focus after stopping row edit mode with pagination enabled

[m4theushw]

In #4252 I forgot to clamp the indexes. This was raised in #4252 (comment)

I also took the opportunity to improve which cell receives focus when editing the first column of the first row or the last column of the last column. Previously, focus would jump to the last cell or the first cell when these conditions are met. Now we keep focus on the current cell.

Steps to reproduce

1. Open https://codesandbox.io/s/basicroweditinggrid-material-demo-forked-zdftxh?file=/demo.tsx
2. Double-click on the "Last login" cell of the last row
3. Press Tab
4. 💥

CodeSandbox with the fix: https://codesandbox.io/s/basicroweditinggrid-material-demo-forked-soxqwq?file=/demo.tsx

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	226.2	441.1	387.2	337.28	90.239
Sort 100k rows	ms	442	904.6	681.1	670.88	158.111
Select 100k rows	ms	103.1	234.5	131.6	162.12	59.86
Deselect 100k rows	ms	87.8	203.4	171.1	153.56	39.455

Generated by 🚫 dangerJS against 0317dc7