[UnifiedDocViewer] Component & Redesign

[kertal]

This issue aims to make the layout of the DocViewer more compact. The following measures should be applied

• Header: Change the title in the flyout from Expanded document to Document. Move the document pagination from the actions row to the right side of the title.
• Header: Rename “View” to “Actions”. Change labels from “Single document” and “Surrounding documents” to “View single document” and “View surrounding documents”. This change is in response to the ask to make this section scalable without taking up more vertical space. See the screenshots below for the icon-only version which we should apply in the event of having more than two actions.
• For desktop, remove the Actions column. Instead, use the floating actions we introduced for Controls. These floating actions should appear on the left side of the row. For small screens where hover is unavailable, we can fallback to the current implementation. See:

Icon-only actions in header

Originally posted by @andreadelrio in https://github.com/elastic/kibana/issues/160306#issuecomment-1606575952

### Tasks
- [ ] https://github.com/elastic/kibana/issues/163239
- [ ] #163798
- [ ] https://github.com/elastic/kibana/issues/164660
- [ ] https://github.com/elastic/kibana/issues/164617
- [ ] https://github.com/elastic/kibana/issues/168107
- [ ] https://github.com/elastic/kibana/issues/163275
- [ ] https://github.com/elastic/kibana/issues/168607
- [ ] https://github.com/elastic/kibana/issues/167846
- [ ] https://github.com/elastic/kibana/issues/174745

[elasticmachine]

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

[kertal]

Closing this for now as the majority of tasks is done, and 2 remaining tasks https://github.com/elastic/kibana/issues/163275 -> filtering on value in UnifiedDocViewer is now part of OneDiscover https://github.com/elastic/kibana/issues/167846 -> Adding the flyout to the package could be closeable, as our priorities shifted to OneDiscover