Migrate to using generated code

tests/build_generated_code.rs

@@ -1,13 +1,19 @@
 use std::fs;
 use std::process::Command;
 use std::path::PathBuf;
+use roto::google::protobuf::descriptor::{
+    FileDescriptorSet
+};
+use roto::google::protobuf::compiler::plugin::{
+    CodeGeneratorRequest, CodeGeneratorResponse, CodeGeneratorResponseBuilder, code_generator_response::{File, FileBuilder},
+};
 
 #[test]
 fn test_generated_code_builds() {
     // 1. Generate Rust code from data/request.bin
     let request_path = "data/request.bin";
     let data = fs::read(request_path).expect("Failed to read request.bin");
-    let request = roto::proto_gen::google::protobuf::descriptor::CodeGeneratorRequest::new(&data)
+    let request = CodeGeneratorRequest::new(&data)
         .expect("Failed to parse CodeGeneratorRequest");
 
     // Mimic the logic from protoc-gen-roto to build a FileDescriptorSet
@@ -27,7 +33,7 @@ fn test_generated_code_builds() {
         // Write data
         set_buf.extend_from_slice(file_data);
     }
-    let set = roto::proto_gen::google::protobuf::descriptor::FileDescriptorSet::new(&set_buf)
+    let set = FileDescriptorSet::new(&set_buf)
         .expect("Failed to create FileDescriptorSet");
 
     let generated_files = roto::generator::generate_rust_code(&set, None, false);

tests/test_nested_protos.rs

@@ -1,5 +1,7 @@
 use roto::generator::generate_rust_code;
-use roto::proto_gen::google::protobuf::descriptor::FileDescriptorSet;
+use roto::google::protobuf::descriptor::{
+    FileDescriptorSet
+};
 use std::fs;
 
 #[test]