c/driver/framework: document and test the driver framework

### What feature or improvement would you like to see?

Document the C++ framework for writing drivers and add unit tests for the internal utilities

Start by locating the C++ driver framework and its internal utilities, then review any existing documentation and unit tests around them. Done means the framework for writing drivers is documented and unit tests cover the internal utilities described in the issue.

Written by the indexing model from the issue text.