fix: include trait bounds in where clause of From<JsValue>

[Pantamis]

This should once and for all (I hope 😅) fix #25
I also updated the e2e test to catch the case of trait bounds (and even lifetime constraint)

However I am not very satisfied by this fix because it actually replaces Self in where clause with the type on which we are implementing IntoWasmAbi and From<JsValue>which I think is a bit hacky and maybe not how the syn::Generics interface is intended to be used.

A "more syn friendly interface" could be to not implement From<JsValue> but Into directly and use Self as usual, this will however require to disable a clippy warning.

So every solution I think of are meh, one thing for sure: we really need those e2e tests with more case coverage 😬

Let me know if you have a better idea to fix this @siefkenj @nappa85

[siefkenj]

I don't think this is the right solution. You should grab the user's specified where clause from cont.serde_container.original.generics.where_clause and append that to the one you're generating for From.

[Pantamis]

Thanks for the hint ! My main issue was that I did not know how to get the #ty_generics tokens to build the where clause before calling split_for_impl but you can actually use the #generics to get the same tokens directly, I did not know that !

So I can actually borrow the generics from the input container one more time to build the correct where clause on the cloned and mutated one.

I think it is now a much more satisfying solution 👍