Add a method for getting the request query

This commit also improves the existing _get_request_object() method by
adding support for getting the key data from the query object if it
exists in the attrs or request.
Add a template for the DataQuery
Add enpoint, form, tests, and urls for DataQuery
Add 'queries' link to root endpoint
Rename avocado.metrics => avocado.events

This changed in cbmi/avocado@a5aca608
Remove link to HTML exporter in test case

This changed in cbmi/avocado@20c6c985