Our API unit test setup has grown over time in ways that made it hard to

build upon.
We had dedicated methods for the Local Site setup that took care of

fixture loading, authentication, subclass setup state, and some

assertions, but we didn't have this for non-Local Site tests, each of

which had to implement this setup manually, leading to inconsistencies.
The setup functions we did have used tuple results, which made them hard

to build upon. This is also an issue for the subclass's return values

(though changing that is out of scope for this work and isn't necessary

for upcoming changes).
This change moves the setup functions out of the Local Site mixins and

into the base test class mixins, giving them options for controlling

some more aspects of test setup to meet all the current needs. They also

now return dictionaries of information.
These changes make it easier to expand upon this for some upcoming work.

Unit tests pass.