[Feature] Add ability to specify external dependencies

[IlyaGulya]

Tracking issue for external dependencies.

We should allow either of these two options:

1. Provide path to custom Package.swift, parse it and configure cinterop accordingly
2. Add APIs to give user more flexibility around Package.swift configuration.

[jvondermarck]

When it will be available ? I really need to use external dependencies...

[IlyaGulya]

When it will be available ? I really need to use external dependencies...

Unfortunately, I'm quite busy for the next couple of weeks 🙁
I will be able to start investigating this issue on the beginning of October.

[jvondermarck]

Awesome, if you do this feature, it will be insane because so far there is literally NO WAY to call Swift code from your kotlin code that use external libraries.

[misha-dorokhin-fourthline]

We are really interested to see this feature working. Is there any update? How can we help?

[estreteca]

Super interesado en esta funcionalidad, realmente es muy complicado usas sdk externos en KMP

[IlyaGulya]

Small update: I'm working on it, but this is quite challenging task to do.
@jvondermarck @misha-dorokhin-fourthline @estreteca
It would be nice if you will share with me your use cases and how you are expecting to use this feature.
What project structure do you have?
All these questions are crucial to make good API.

Currently I have extremely basic implementation which supports only one KMP module and does not support any other use-case: #47
I'm planning on making SNAPSHOT releases on this weekend