Remove use crate::engine::* from generated class files

Incremental rebuild of `cargo check` after change in godot-core timings:

before: 32.63s average
after:  11.068s average
diff:   -65.48%

Author: lilizoey

godot-codegen/src/class_generator.rs

@@ -294,7 +294,6 @@ fn make_class(class: &Class, class_name: &TyName, ctx: &mut Context) -> Generate
         #![doc = #module_doc]
 
         use godot_ffi as sys;
-        use crate::engine::*;
         use crate::engine::notify::*;
         use crate::builtin::*;
         use crate::obj::{AsArg, Gd};

godot-codegen/src/util.rs

@@ -283,15 +283,15 @@ fn to_rust_type_uncached(ty: &str, ctx: &mut Context) -> RustTy {
             let enum_ty = make_enum_name(enum_);
 
             RustTy::EngineEnum {
-                tokens: quote! { #module::#enum_ty },
+                tokens: quote! { crate::engine::#module::#enum_ty },
                 surrounding_class: Some(class.to_string()),
             }
         } else {
             // Global enum
             let enum_ty = make_enum_name(qualified_enum);
 
             RustTy::EngineEnum {
-                tokens: quote! { global::#enum_ty },
+                tokens: quote! { crate::engine::global::#enum_ty },
                 surrounding_class: None,
             }
         };
@@ -323,7 +323,7 @@ fn to_rust_type_uncached(ty: &str, ctx: &mut Context) -> RustTy {
     } else {
         let ty = rustify_ty(ty);
         RustTy::EngineClass {
-            tokens: quote! { Gd<#ty> },
+            tokens: quote! { Gd<crate::engine::#ty> },
             class: ty.to_string(),
         }
     }