Bundle generated JS files qualified

[palas]

Changelog

- description: |
    Updated `proto-js-bundle` nix output to create a single `.js` bundle file with qualified names for each `.proto`
  type:
  - feature
  projects:
  - cardano-wasm

Context

Previous solution in PR #913 doesn't work, because each generated .js file uses the same namespace, and they override each other. So this PR modifies the script that generates them to produce a single .js file that has their exports qualified by their module name, so that we only need to import one file, and so that the namespaces don't collide.

This PR also updates all the code that used it, and generalises the wasm library so that it also stores the clients qualified, and thus it can do multiple different types of queries easily.

How to trust this PR

I think, again testing is the most important bit. Also ensure the code style is good, and the comments are up to date, enough, and clear.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff