feat: add mobile platform build support

[Johnosezele]

Add build scripts and documentation for iOS and Android mobile platforms. Closes #3

[reez]

Thanks!

I know we don't have sample app yet, but did you happen to you run through this end-to-end (i.e. generated bindings, built the iOS/Android artifacts, and plugged them into a demo app)? Just trying to think about all the ways to double check that what we're doing here w the new scripts/locations match what an app project expects. I'm trying to double check it myself and running into issues, for example running ./scripts/build-android.sh currently fails immediately and such.

[reez]

@Aniket-pd are you interested in reviewing/testing this?

[Johnosezele]

... and plugged them into a demo app

Not yet. Though the outputs land in the directories a flutter module will expect... I shall test with the existing demo we have.

... for example running ./scripts/build-android.sh currently fails immediately and such

Oh yeah, you'd have to make the script executable or just run bash ./scripts/build-android.sh ... I think this wasn't properly formatted on the readme, I shall do that

[reez]

Awesome, all tests pass now. I'd like to give a few other folks (@kumulynja @Aniket-pd others) a chance to review too before I merge, but this PR is shaping up nice and passing CI!

[Johnosezele]

Thanks @reez I've updated the bdk_demo so we can validate the android artefacts by loading a sample descriptor directly from the app

[reez]

Thanks @reez I've updated the bdk_demo so we can validate the android artefacts by loading a sample descriptor directly from the app

love it!!

[Aniket-pd]

Sure, I’d be happy to review it.

[Aniket-pd]

I ran the iOS build script locally and the generated artifacts look correct. Didn’t run into any issues on my end