Don't require the end user's code to manually depend on the group or ff crates

Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 sigma_compiler_derive = { path = "sigma_compiler_derive" }
+group = "0.13"
 
 [dev-dependencies]
 curve25519-dalek = { version = "4", features = [ "group", "rand_core", "digest" ] }
-group = "0.13"

sigma_compiler_core/src/codegen.rs

@@ -345,7 +345,7 @@ impl CodeGen {
         quote! {
             #[allow(non_snake_case)]
             pub mod #proto_name {
-                use ff::PrimeField;
+                use group::ff::PrimeField;
                 #dump_use
 
                 #group_types

src/lib.rs

@@ -1 +1,2 @@
 pub use sigma_compiler_derive::sigma_compiler;
+pub use group::{self, Group};