Add new REST tests, this time in Haskell

The NodeJS/JavaScript based REST unit tests were pretty horrible to
develop.  I couldn't figure out a way to develop these tests without
ending up in a nested callback hell.
Add createUserTests and loginUserTests combinators

These can be used to create TestGroups that are run with cookies
received from the login or create user procedure.
Get rid of the unnecessary test user mode

If tests just perform a login before running, there's no need for the
debug test user system.
Test we get 403 back from GET /rest/* when not logged in
Remove withOpts
Add a test for adding new exercise types
Remove configurator import & package dep
Add workout creation test
Simplify lens matching of exercise JSON
Define an 'exercises' traversal for inspecting exercises in a workout
Add delete tests plus do some clean up
Move workout tests into separate module
Add weight setting tests
Test weights in /rest/app
Delete JS-based REST tests

The Haskell based tests have pretty much the same or better coverage
as the old Javascript tests, so get rid of the JS tests.