Feat: sdk generator

[raynaudoe]

⚠️ BETA ⚠️

This PR introduces a Claude Code / Cursor "slash command" /canton-sdk-generator:generate-api that does the following:
1 - Locates and builds the DAML projects in root dir
2 - Runs DAML's JS codegen tool
3 - Runs the scripts generate-canton-api and generate-canton-tests
4 - Enhance the output of the previous step by running a custom prompt

The final output consist on a folder <your-daml-project-dir>/sdk with the generated sdk code and tests in the __test__ dir.

TODOs:

• Improve scripts and prompts to better pack the sdk code
• Test generator should be able to generate integration tests against a running ledger
• Steps [1,2,3] can be packed into one script -> less tokens usage
• Try the workflow: simple DAML project -> slash command -> sdk -> ask AI to build a UI by using only the sdk code