DDF-22 Removed unused, commented code for clarity.
DDF-22 Removed unused private field in OpenSearchSource
DDF-22 Added QueryByID functionality

Using the DDF REST, added a REST call to retrieve a single record by ID.
Added and refactored unit tests for the REST call.
DDF-22 Removing the deleted files from a refactor
DDF-22 Added Integration tests for QueryById FedSearch call

I refactored and added to the Pax-Exam tests we currently have. The newest
file is TestFederation.java