[Discover] Support multiline content in document table

[kertal]

In previous Kibana versions, tested 7.5, multi line content was displayed in the document table:

In our upcoming version 7.13 this is no longer supported in the legacy table:

However, since we currently switch to the EuiDataGrid #97628 , there is lack of support of multiline content by design, so while this issue is here to track a regression, the better way would be to improve multi line support in the new grid.

Note that multiline should at least be displayed when expanding a cell

Reported in https://discuss.elastic.co/t/kibana-n-charecter/270703

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[davtex]

I do not quite understand how this is not getting tons of attention - this completely breaks Kibana for our Java application as we rely heavily on various multi-line logs that are now completely unreadable. I can't be the only one for whom this presents a major issue moving forward.

[kertal]

we're currently researching what broke this (to fix it of course)