Add Python bindings generation command

[overcat]

What

See #1633 (comment)

Why

If this link can be provided in the CLI, it may be easier for users to find it; otherwise, they might not know that Python bindings can be generated.

Known limitations

N/A

[leighmcculloch]

One tweak requested, see the inline comment.

I think we should merge this. Today the cli is where folks go to generate bindings, and so it makes sense as part of that story to support discoverability of a commonly used sdk.

---

We haven't started discussions about this yet, but when I saw that you implemented the Python SDK's codegen tool outside the CLI, it prompted me to start thinking about doing the same for the JS SDK. I think the pattern you've used is a good pattern to follow for the following reason. These codegen tools are generating code for using the SDKs, and so they are tightly coupled with the SDKs, and specific versions of the SDKs. We've already found it difficult to coordinate stellar-cli releases with the js-stellar-sdk, and if we moved the JS/TS binding generation from being "cli adjacent" to being "sdk adjacent" then I think it would tell a better maintainer story.

The thing I'm wrestling with is discoverability, the same issue for why this PR exists.

If we do this we wouldn't likely do it before v23. I just wanted to drop some thoughts because I think the setup we have today with bindings built into the cli may not be the setup in the near future, and so this area of code and functionality may change.

[overcat]

Hi @leighmcculloch, I completely agree with your point of view. Another reason I didn't implement it directly in this repository is that, for me personally, developing generation scripts using a scripting language may be more efficient than using Rust. I can write and debug at the same time without having to wait for long compilation times. 😂