Cleanup tests in project template

[bonicim]

I used copier to create a PlatfromDriverAgent project and noticed some issues when trying to push to a remote repo using precommit:

• The example tests still refer to a cli module. This should be rewritten with test stubs that take the form of volttron agent tests such as: https://github.com/VOLTTRON/volttron/tree/main/services/core/ActuatorAgent/tests
• The example test should be renamed to something more generic (ie. test_agent.py)
• The pytest precommit hook fails because it has the wrong command (it should be poetry run pytest)
• The agent code has a very small indentation error in the template (see _log on or near line 58 in https://github.com/VOLTTRON/copier-poetry-volttron-agent/blob/develop/project/src/%5B%5B%20python_package_import_name%20%5D%5D/agent.py.jinja#L58)
• Remove unnecessary imports in tests