[EuiDataGrid] Column sort direction indicator

[sulemanof]

If the grid's toolbar is disabled (where the sorting selector is presented), the only way to see the sorted column is to expand the column actions dropdown - sort direction is highlighted with bold text:

It is hard to determine which column is sorted for the user.
Should the data grid ship the same indicator as in EuiBasicTable ?

Or it is a developer task to present it in a column via display property?

[snide]

I still think it's important to keep the caret for indicating that a header has a menu (not all of them will). Putting the sort to the left of the title (only when it's active) should give a decent indication of what's up and still remain fairly clean.

[sulemanof]

Resolved in #4343