EUI 31.7.0 backports for 7.12

[snide]

Backports to apply for EUI 37.1.0 to add to 7.12 release.

cc @flash1293 for tracking.

• Revert background color on Data Grid background content. Revert grid background color #4542
• [EuiDataGrid] Performance issue when row count changes while pagination is enabled [EuiDataGrid] Performance issue when row count changes while pagination is enabled #4532

[flash1293]

Thanks for opening this @snide - as we decided to not make data grid the default discover experience in 7.12, #4532 isn't critical, so no need to squeeze it in.

[cchaos]

Are we done with these?

[thompsongl]

Well past 7.12 time; closing. Reopen if we need to consider backports for another release.