Add command 'add testsuite'

**Is your feature request related to a problem? Please describe.**
In the current boilerplate, there is no automated testing framework setup

**Describe the solution you'd like**
I want to be able to run sth like 'biotope add testsuite' which will add the testing frameworks.

The issue does not name an implementation file, command entry point, or testing framework; begin by locating how existing biotope add commands are registered and reviewing the current boilerplate setup. Clarify which testing frameworks should be added and what the generated setup must contain, then verify that `biotope add testsuite` creates a runnable automated test setup.

Written by the indexing model from the issue text.