Proposed struct for searching db for test runs: struct TestRunSearch

[packapotatoes]

I was looking at @TheAustinJones 's changes for GetTestInfo and realize we could use a general purpose struct for all (most?) searches. A TestRunSearch struct would have all the same fields as the TestRun struct, but each field is wrapped in Option(). We can then deserialize the parameters directly to this struct and search the db by any field that isn't None. This way search calls can be handled more universally.