Swagger

[dkackman]

This PR adds OpenAPI/Swagger doc generation.

Of note:

• the sage rpc does not host or serve the openapi doc or swagger plugin (it would require a way to bypass the mutual tls auth which isn't worth it)
• the doc json can be generated with cargo run --bin sage rpc generate_openapi -o dist/openapi.json
• as part of the release process this can then be uploaded to docusaurus
• install this vscode extension to be able to view the generated json in the swagger-ui from within VSCode/Cursor (open dist/openapi.json and the extention will have an option to view in the plugin