docs: improve IDL documentation and add allocate test

[raushan728]

• Added documentation for core instructions in idl.json to improve developer experience.
• Regenerated JS and Rust clients to propagate documentation changes.
• Added a new test suite for the Allocate instruction in the JS client.

[joncinque]

Thanks for your contribution! We shouldn't make any changes into the generated folder, since those are all auto-generated, so please revert those, and then we can try to land the added test

[raushan728]

Thank you! I've reverted the changes to the generated folders as requested. Only the documentation in idl.json and the new allocate test are now included in this PR