Rewrite project acceptance tests to use in-process API

This cuts down on a lot of boilerplate for making HTTP requests, and
in fact doesn't require HTTP at all for these tests. Includes coverage
for all the new API features added in this series.

Also rewrite the ProjectAssert helpers so we return a Subject for the
list of project names in a ProjectInfo list. The return type of this
method is hideous (an unfortunate fact of life with Truth), but the
resulting tests are much more expressive. For example, this allows us
to use inOrder() to test the sorting of listing projects, where the
old assertProjects did not.

Change-Id: I8cd72331f9885dca93609617c684cf92806ec6b3