Remove non-unified search and rename unified search to search

Removed all the things which were need for the old non-unified tabbed search interface. This included:

- presenters
- rummager initializers
- controller method
- view files
- JavaScript to initialise the tabs
- CSS
- routes

Then refactored the presenters which are now only being used by the unified search to remove unused method and simplify some methods.

Then moved the unified search things to be called just search as it is the one and only.

Think I have deleted/renamed/refactored everything which search used.

https://www.pivotaltracker.com/story/show/71307294