feat!: check_dependencies returns the list of dependencies

[sdn4z]

Up until this PR, check_dependencies was returning a bool, making reference to if there were errors found or not. Now, it returns a list of the errors found instead.

Some other breaking addition where made at the same time, like changing the name of the argument dependencies_cli to dependencies.

BREAKING CHANGE: check_dependencies returns the list of dependencies and function arguments' names have changed

[scastlara]

Why is this a breaking change? The executable twyn itself did not really change no? Maybe if you used twyn as a lib, but do we consider that part of the public interface?

[sdn4z]

Why is this a breaking change? The executable twyn itself did not really change no? Maybe if you used twyn as a lib, but do we consider that part of the public interface?

I thought on making it breaking because of that actually! I guess we have to decide where to draw the line here. Imo, since we support different Python versions we implicitly acknowledge that it is indeed meant to be used as a library.