Module errors when ConfigModifyDrushCommands is loaded without an install profile

Problem/Motivation

It's no longer needed to install Drupal with an install profile. The project could be installed from config or recipes instead. However, the ConfigModifyDrushCommands class will crash if installProfile is not given a string.

Steps to reproduce

Proposed resolution

Allow the installProfile to be NULL. Downstream code is within Drupal and that already handle the null case.

Remaining tasks

User interface changes

API changes

Data model changes