test_proxyquery: rename test user names

This renames user and user1 to user1 and user2, respectively.

I find this a bit easier to read.
test_proxyquery: separate auth test classes

I broke the auth tests up into multiple classes, and abstracted a
TestAuthBase class (which contains all of the setup utils and fixtures).
test_proxyquery: set up prosrv once in auth tests

The `prosrv` (proxy server) variable was being defined in every single
one of the auth tests. This change makes it a variable of the test class
instance and defines it once. This removes quite a bit of duplication.
test_proxyquery: use "true" instead of "t"

For removing suid and acl settings. "t" was kind of ambiguous.
The value just needs to something that's not an empty string.