Most of the tempest utilities need at least a partially setup
configuration file to work properly. This is because most of them
make api requests in order to perform the expected operations.
This causes a bit of a chicken and egg problem when we rely on
these utilities for configuration purposes since we don't know if
we have enough of a configuration file to run things. This previously
wasn't an issue because all we needed to run was verify-tempest config
and it wasn't in a critical path just for api extension discovery and
it wasn't relied on. But, with the addition of tempest preprovisioned
credentials we rely on a tempest util to create the credentials we
use for running things. We need to ensure the util has as complete of
a config file when it's run to ensure that everything is in the
correct state.
This commit moves the running of all tempest utils and the associated
iniset calls to the end of the configure_tempest function to ensure
that the utils have as complete a config file as possible.
Additionally, it makes all tempest util calls are venv isolated. (which
is mostly future proofing for when things are branched on stable)
Change-Id: I5844aed4e134fbc7210aa0eca83500e260915b7b
e8f3f7aa0d