[EuiDataGrid] Redesign grid header

[kertal]

Is your feature request related to a problem? Please describe.
We are giving Discover a visual refresh, this issue aims to summarize the changes in the grid header section.

Describe the solution you'd like
For our upcoming Discover redesign there are 4 changes requested (Figma)

• Change the icon for additional actions to boxesVertical
• Show the additional actions on hover or focus of the heading cell
• Allow columns to be right - aligned for e.g. numeric values
• Show the sorting arrow on the right side of the columns name

Describe alternatives you've considered

• A local CSS based change, but for these changes it doesn't seem to be possible
• Make this part configureable so we could apply these change locally

[kertal]

@cee-chen do you thing this could/should also be a render props powered changes? FYI @jughosta

[cee-chen]

Hmmmmmm. This one feels a bit trickier because I could see all these changes simply being default changes to the baseline datagrid instead of configurable changes. They feel generic enough that it makes sense and changing it just once would make datagrid more consistent across all of Kibana/Elastic.

@andreadelrio what do you think? Are these Discover-only changes or data-grid-wide changes?

[kertal]

Hmmmmmm. This one feels a bit trickier because I could see all these changes simply being default changes to the baseline datagrid instead of configurable changes. They feel generic enough that it makes sense and changing it just once would make datagrid more consistent across all of Kibana/Elastic.

for me this makes sense 👍

[andreadelrio]

Hmmmmmm. This one feels a bit trickier because I could see all these changes simply being default changes to the baseline datagrid instead of configurable changes. They feel generic enough that it makes sense and changing it just once would make datagrid more consistent across all of Kibana/Elastic.

@andreadelrio what do you think? Are these Discover-only changes or data-grid-wide changes?

I think this should be data-grid-wide changes and the new default.

[cee-chen]

Closed by #7371