Update uri mapping

To move away from ES query_string, new mapping for the uri fields
should be introduced.

For the index_analyzer we use the pattern_capture filter to be
able to split the uri field to our desire.
Remove clause parser
ES Query type for streamer backend

ES Query_type is introduced as an option for our stream filter.
This way the streaming backend can generate our regular,
query_string and match query.

Our uri field will use match query for perfomance improvement
Merge pull request #1282 from hypothesis/searchable_uri-2

Update uri mapping, use match query
Start building up a pattern library

Starting with the form elements, the new view is available at
/dev/pattern-library and currently only shows form fields.
Move pattern library view to h.testing

This ensures that it's only loaded in development.