Add a flag for printing all available test frameworks in the project

[Gedochao]

Is your feature request related to a problem? Please describe.
I'd like to make it possible to print all available test frameworks in a Scala CLI project, so I can later pre-configure them with --test-framework///> using testFramework.

Describe the solution you'd like
A --print-test-frameworks flag should do, similar to --print-classpath.
A warning may be necessary when running on Scala.js/Scala Native, as this may take a bit, especially for larger projects.

Describe alternatives you've considered
One can always run scala-cli test with increased verbosity, I suppose.

Additional context

• Run all found test frameworks, rather than just one #3621