props should be derived from URL (and improved loading)

[dpwrussell]

Problems:

• Manually modifying a URL will not cause a transition
• <img> and potentially other html tags that have a lazyish behaviour cause wrong images to be displayed and then updated.
• Not best practice

Requirements:

• [ ] Write selectors to extract route params required
• [ ] Write selectors to calculate state
• [ ] Disable the file data being reduced literally every time a route is visited
• [ ] Reduce data once and then check for presence in future as the app is completely static
• [ ] Remove info from reducers and see what breaks

[dpwrussell]

This is resolved for most places which were showing symptoms in #259, but there are still a large number of places that would benefit from having their props for rendering calculated in selectors using the state and the url instead of loading data directly from tsv each time or where the data is never loaded into the state.

• [x] Cell Lines
• [x] Drugs
• [ ] Datasets