clean up temp directories and stop sharing them across tests
add in load_all_subrequest_results_modified_since to the storage layer (and tests)
clean up the App::Debugger so that it is easier to extend, also remove the { data => …, links => … } stuff as we are not using it, then adding tests
make the tests clean up after the run (and before, in case of a bad run)
allow fetching of subrequests ‘modified-since’ through the App::Debugger as well
fix the test (forgot to run it after splitting it out)