[core] Avoid useless columns preprocessing on Grid mount

[flaviendelangle]

Avoid double useEffect run during grid init

Fixes #1562

[oliviertassinari]

It seems to fix #1562, proof https://codesandbox.io/s/datagrid-legacy-vs-concurrent-root-forked-4x35b?file=/demo.js

[flaviendelangle]

I was not the main goal but nice 😄

[flaviendelangle]

@oliviertassinari if #2344 has the same behavior, it is indeed simpler and I'm OK to close this one

[oliviertassinari]

@flaviendelangle I'm not exactly sure it has the same behavior. I looked at it because I was suspicious we could have a simpler logic/wanted to understand what was going on in this hook. I don't plan to push #2344 much further. If you can continue the exploration, and pick whoever works best, I think that it would be great.

[flaviendelangle]

After a few checks, the behavior seems to be very similar
If we see edge case not optimized with your version we'll see 👍
I'm closing mine and approving + merging yours

[oliviertassinari]

Alright, at least, it easy to follow. Note that we have a few tests in the codebase that assert we don't render too many times. We could consider doing the same if we see regressions.