As a user, I can export Tests in JSON format using the Xray REST API

Users must be able to export any type of Test issues using the Xray REST API. The new method must return a JSON file with all Test issue keys and respective definitions.

GET /rest/raven/1.0/api/test

This method must expect 3 parameters:

1. keys - a list of Test issue keys
2. filter - a saved filter id
3. jql - a JQL query to search for Tests