Caches hardware information collected during inspection
so that the initial lookup can occur without any delay.
Also adds logging to track how long inventory collection takes.
Conflicts:
ironic_python_agent/hardware.py
ironic_python_agent/tests/unit/base.py
ironic_python_agent/tests/unit/test_hardware.py
ironic_python_agent/tests/unit/test_inspector.py
Co-Authored-By: Dmitry Tantsur <dtantsur@protonmail.com>
Change-Id: I3e0d237d37219e783d81913fa6cc490492b3f96a
(cherry picked from commit c76b8b2c21)