Now we can search the history Testing Farm requests submitted by particular token via RHELTEST-362 and documented in https://docs.testing-farm.io/Testing%20Farm/0.1/faq.html#_how_to_find_previous_testing_farm_requests

It's still not convenient to only have "created_after" adjustment. We'd like to have a filter which can limit to for example compose, plan, test name and even better the whiteboard (added via RHELTEST-395)