Index pattern UX: Implement CRUD flow

[cjcenizal]

We should implement a consistent CRUD UX throughout our apps, similar to the one in Visualize and Dashboard. For index patterns, it would consist of:

1. A landing page with a table that lists all of your index patterns.
2. A detail page for viewing the details of an index pattern.
3. An editing page for changing an index pattern.

[alexfrancoeur]

I may be wrong here, but would assume the functionality for editing an index pattern would require some sort of unique ID that would be referenced in other saved objects. In order to continue to support importing and exporting saved objects in one way or another, I believe we'd need to also support exporting index patterns (#4288) and/or enhancing the new API (#11632) to support exporting index patterns.

[cjcenizal]

Just some notes:

• Implementing this change will consist of largely copying code from the Dashboard or Visualize landing pages
• We can use React components for the landing page
• This will allow us to delete a bunch of old HTML and LESS
• This will also reduce our dependency upon Bootstrap