[Discover] Add "Toggle Field" action to Expanded Document view for quick access

[VijayDoshi]

In the Expanded document view in Discover you have to click on the actions "..." to get to the "toggle field" action. Users would like easier access to this action. I suggest we provide a Toggle field action in a new column to the right of Actions in the expanded document view. Perhaps use the same "+" icon/behavior as is in the field list so the UI is not cluttered and the action is consistent.

Enhancement request: https://github.com/elastic/enhancements/issues/15930#issuecomment-1101658912

[elasticmachine]

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

[kertal]

This was recently discussed, the request was that adding a filter takes more clicks now. So there are different requirements. What we could do is to make ... responsive. For small screen sizes we could display ... like now. For larger screen sizes we could display all 5 buttons.