Add toggle to show/hide minimap

The user needs to be able to open and close the mini map in both the Studio and the Detail view of a pipeline.

Add a button to the toolmenu. The mini map button is a toggle

normal state: minimap is not displayed

selected state: minimap is displayed (background changes to #dddddd)

hover state

Acceptance Criteria

• The user can open and close the minimap by selecting the minimap toggle in the toolmenu

• The minimap can be closed by selecting the  on the top right corner of the minimap

• The minimap is automatically open when there are more than 6 (@Bhooshan Mogal shall we increase the number to 10?)