Automate Typescript definitions for wasm-exported Types

Since 0xMiden/miden-client#1440 was merged, we don't have to worry about manually exporting the sdk's types we expose through wasm.

But, we still have a few things left to check and/or do:
1. We still have to manually update the type definition for the WebClient exposed under index.js
2. The type definitions for the tests (under global.test.d.ts) have to still be manually added.
3. The types under index.d.ts are still manually exported, we have to find a way to avoid this (maybe we can migrate from plain JS to Typescript? at least for the index.js file).

A disclaimer about bullet point 3: This might have been fixed by 0xMiden/miden-client#1440, but I haven't been able to check it properly, I think the ideal way would be to create a new project and import the sdk to check if the types are being exported. We could also check this with this tool: https://api-extractor.com/

Examine the index.js file and the global.test.d.ts file to understand the current manual type exports. Investigate the wasm type generation from the linked PR #1440. Use api-extractor.com or create a test project to verify automatic type exports. The goal is to automate type definitions for the WebClient and test types, potentially by converting index.js to TypeScript.

索引モデルが issue の本文から書いたものです。