[CLN] Get API generation working again

[AlabasterAxe]

Description of changes

The API generator would consistently fail for me when attempting to process "const" declarations. I found a workaround which is to re-write references to anyOf const objects as an enum of strings.

We were already lightly processing the openapi.json file in the shell script before but I've moved that logic into a TS script which makes it easier to do more complex transformations. I stopped short of reimplementing all of the logic in TS and just do an exec at the end of the TS code. To avoid confusion about the relationship of the files, I opted to move the shell code into a string constant in the TS script.

Test plan

• [x] I've generated the client libraries locally using the script pnpm genapi

Documentation Changes

No changes necessary.

[github-actions[bot]]

Reviewer Checklist

Please leverage this checklist to ensure your code review is thorough before approving

Testing, Bugs, Errors, Logs, Documentation

• [ ] Can you think of any use case in which the code does not behave as intended? Have they been tested?
• [ ] Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• [ ] If appropriate, are there adequate property based tests?
• [ ] If appropriate, are there adequate unit tests?
• [ ] Should any logging, debugging, tracing information be added or removed?
• [ ] Are error messages user-friendly?
• [ ] Have all documentation changes needed been made?
• [ ] Have all non-obvious changes been commented?

  System Compatibility

• [ ] Are there any potential impacts on other parts of the system or backward compatibility?
• [ ] Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

  Quality

• [ ] Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)