Move the parsing of sierra input function types from forge to USC

[Arcticae]

Which components does the task require to be changed? (think hard pls)

snforge

Description

We should add a hidden API in USC in order to achieve full independence of sierra, and/or parsing the structures that we don't own.

It should be contained in USC via a hidden API (like unsafe_... features in scarb for profiler)

We use those types structures for:

• Knowing the type name (fuzzing arguments generation)
• Generating the entry code

It should be assessed whether we can be fully independent of sierra (and sierra-dependent) crates

[piotmag769]

For creating the entry code all the compiler really need to know that is sierra specific are the names of the args (GenericTypeId is basically a newtype for SmolStr), we can prob just change the interface in the compiler

[Arcticae]

Not relevant after plugins migration