Provide stdlib via module provider to assembler

[vlopes11]

Describe your changes

This initial step for the solution of #298 removes stdlibrary as dependency of assembler.

This decoupling will increase the assembler module extraction flexibility. As next step, an efficient lookup of hasher module+label will be introduced in order to fetch parsed/compiled procedures.

[bobbinth]

Thank you! Looks good! I left a couple small comments inline.

One more general comment (could be addresses in the future): I don't love making Assembler generic. However, we do want to have the flexibility of defining custom logic for ModuleProvider.

I'm wondering if there is a way to achieve both somehow. For example, could we provide ModuleProvider as dyn reference? (I have very little experience working with such patterns).

Another potential option is making ModuleProvider a struct rather than a trait. This struct then could be built in a variety of ways by whoever needs to instantiate the assembler. This will make the structure less flexible we'll need to make assumptions about how ModuleProvider works.

Are there any other approaches?

[vlopes11]

@bobbinth there is a nice possibility to have a module provider as concrete that will have runtime loaded modules via dyn ModuleProviderInstance. These can be many, and this will offer further flexibility. Preparing a push with that approach

[bobbinth]

I like this approach! Thank you! I left a few comments inline (some nits and a question about potential simplification).

[bobbinth]

I like it! Thank you! I left just two small comments inline.

[bobbinth]

All looks good! Thank you!