We are refactoring the supervisor test suite into unit tests (for
algorithms an domain model tests) and integration
tests (for interaction with out-of-process dependencies).
This means the current test suite needs to be classified into
these two categories, and fixed whenever possible.
This commit moves the test suite under the `test/legacy` folder, this
folder should be progressively migrated and eventually removed.
Subsequent commits will begin to split these files into unit and
integration whenever possible.
Depends-on: #1996
Change-type: patch
