[DataGrid] Add support for MUI v5

[DanailH]

Closes #441

The current changes provide support for MUI v5 in the DataGrid component. I tested it with both v4 and v5 but what needs to be done for this to be done is to update the docs in the next branch on the core.

I only changed the peerDep in the package.json but kept the v4 version for the root package.json and the one in the storybook and the docs so that master will remain on v4.

I've opened a separate PR in the core for the docs update and add an example that we can use as a test. You can check it here -> mui/material-ui#24428

[oliviertassinari]

I'll open a separate PR in the core for the docs update and add an example that we can use as a test.

Yes, let's open a draft PR in the main repository to add a live demo in v5: https://next.material-ui.com/components/tables/#data-table, as we have in v4: https://material-ui.com/components/tables/#data-table.

[oliviertassinari]

It looks good. I think that before we merge, we can:

1. do the draft PR in the main repo with the package built on codesandbox-ci to make sure it works
2. (optional) if we want to go the extra mile, we could reset hard the next branch on master (in material-ui-x), apply 50a16a1, apply this PR, make sure that all the demos are working. It would help us a bit once we want to swap active development to the next branch (v5).

[oliviertassinari]

I jumped ahead and did 1. in codesandbox. There is an issue with a deprecated API: https://codesandbox.io/s/peaceful-cache-72s4k?file=/index.js

[DanailH]

@oliviertassinari I opened a PR in core with the update in the docs -> mui/material-ui#24428

[oliviertassinari]

It looks good https://codesandbox.io/s/peaceful-cache-72s4k?file=/package.json

[DanailH]

Only thing is that I also wanted to see it here mui/material-ui#24428 but the build fails and idk if is due to the grid package

[DanailH]

2. (optional) if we want to go the extra mile, we could reset hard the next branch on master (in material-ui-x), apply 50a16a1, apply this PR, make sure that all the demos are working. It would help us a bit once we want to swap active development to the next branch (v5).

Will do that

[oliviertassinari]

I think that we should do something about the input. v5 changes the default to outlined, how about we stick to standard?

It's worse with the filters.

[DanailH]

I think that we should do something about the input. v5 changes the default to outlined, how about we stick to standard?

Is this to be changed here or in the core?

[oliviertassinari]

Is this to be changed here or in the core?

Why should it be changed in the core? We changed it into the core because Material Design do no longer document the standard variant. In the data grid, I think that we need something light, not using too much space nor catching too much the eye.

[oliviertassinari]

Gmail approaches the issue like this:

I think that it works with GitHub with an outlined input because the input is smaller:

[DanailH]

Also, Github has lines between the suggested options so there are more block-like with clear boundaries, so a more boxy design suits it.