The IntegrationConfig string representation wasn't very nice. It

didn't list the configuration name, and it used the integration ID

directly. Not exactly friendly.
This improves it to return a string in the form of "Name (Integration)",

which is a bit more useful and friendly all-around.

Checked this in the admin UI in places where it showed up.
Tested with configurations that mapped to an available integration

and ones that mapped to an unavailable integration (making sure that the

integration ID fallback worked).
Unit tests pass.