Allow for setting sys.path in protostar.toml

As mentioned in discord, I’d like to import my own python functions in hints. This is currently not straightforward because I have to manipulate sys.path.

What I’ve currently settled on is to do the path manipulation in __setup__ and imports in the hints themselves.

@external
func __setup__():
    %{
        import os, sys
        sys.path.append(os.path.abspath(os.path.dirname(".")))
    %}

    return ()
end

@external
func test_foo():
    # ...
    
    local expected
    %{
        from tests.my_module.utils import my_func
        ids.expected = my_func(42)
    }%
    # ...
end

It works, but could be made better.

One suggestion is to automatically have the directory in which the test_foo.cairo file is located placed in sys.path so that I can have utils.py sitting in the dir structure right next to my test files. Another thing that would be beneficial is to have a config setting in protostar.toml where I could list paths that I want to have added to sys.path for each test file so that I don’t have to manipulate the path inside __setup__.

[Arcticae]

@milancermak you should be able to execute your original code in the newer protostar versions, since the root of the project is added to cairo-path. This might not work with additional CLI’s --cairo-path just yet, i’m going to start doing some work on that.

[Arcticae]

This should be possible right now, since pythonpath is being synced with cairo-path