Cleanup tests directory from non-unit tests

The tests directory is polluted with other input files. These should be (re)moved.

added To Do label

cc: @ext-rogers_c

mentioned in merge request !62 (merged)

created merge request !62 (merged) to address this issue

mentioned in commit ffacc559

closed via merge request !62 (merged)

closed via commit 88e9e626

mentioned in commit 88e9e626