feat(wasm-dpp): provide external entropy generator to document factory

[markin-io]

Issue being fixed or feature implemented

PR addresses next issues:

• Need to provide external entropy generator to Document Factory (needed for JS)
• Proper error handling for entropy generator (need to know what's going on in case external generator fails to produce entropy)

What was done?

• Return Result instead of panicking in generate() function
• Add entropy generator as an argument to DocumentFactory
• Refactor entropy generator file structure
• Update JS fixture

How Has This Been Tested?

• CI

Breaking Changes

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[antouhou]

I think all good, except I'd use a generic instead of dyn Box

[markin-io]

Agreed to refactor Box<dyn EntropyGenerator> in a separate ticket