[Time To Visualize] Unify Top Nav Between Lens & Visualize

[ThomThomson]

Problem
Currently in Time to Visualize, there are a few small discrepancies in the top nav menus between the Lens and Visualize editors. These menus should be unified to present a consistent UX before the Time to Visualize project can be enabled by default.

Since the menu items on Lens have had design input, the visualize editor's menu items should be updated to match.

See this comment for further clarification
#72256 (review)

There are 4 possible menu states for a 'by value / by reference' enabled editor, 2 of which need to be updated.

• Create by Value: When you've arrived at the editor from the 'create new' button in dashboard the save and return button should show to let the user know they can return to the dashboard easily. Additionally, a 'save to library' button provides an escape hatch for users to exit the 'by value' paradigm.

  Lens
  

  Visualize
  

• Edit by Value: When you've arrived at the editor from the edit button on a by value dashboard panel, the menu should be the same as the 'create by value' use case. Showing the 'save to library' button:

  Lens
  

  Visualize
  

• Create by Reference: When you've arrived at the editor from the 'create new' button in visualize the top nav menu the editors should look as they did in 7.8, with only an emphasized 'save' button. This menu state works fine and does not need to be updated.

• Edit by Reference: When you've arrived at the editor from the edit button on a by reference dashboard panel. This meny state works fine and does not need to be updated.

[elasticmachine]

Pinging @elastic/kibana-canvas (Team:Canvas)