[OneDiscover][UnifiedDataTable] Change expand document/row button

[kertal]

📓 Summary:

The expand icon of the UnifiedDataTable should be changed to the inspect icon of EUI, and move to the right side of the data table row checkbox.

This is how the expand document / result button looks like today:

This is how the expand document / result button looks should look like

1. The icon should be changed to use the inspect icon of EUI
2. The checkbox should moved to the left side, as the first item of the data table row

✔️Acceptance criteria:

• The expand button of the UnifiedDataTable is showing EUI's inspect icon and displayed on the right side of the checkbox

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)