fix: support pydantic-version google pb (#568)

* feat: pydantic version of google pb

* fix: patch pb Struct to support json, dict rountrip

* fix: pydantic-version google pb, json, dict rntrip

* chore: remove `@generated`, remove gen, code fmt

* chore: test case for pydantic-version google pb

tests/test_struct.py

@@ -1,6 +1,7 @@
 import json
 
 from betterproto.lib.google.protobuf import Struct
+from betterproto.lib.pydantic.google.protobuf import Struct as StructPydantic
 
 
 def test_struct_roundtrip():
@@ -22,3 +23,14 @@ def test_struct_roundtrip():
     assert struct_from_json.to_dict() == data
     assert struct_from_json == struct_from_dict
     assert struct_from_json.to_json() == data_json
+
+    struct_pyd_from_dict = StructPydantic(fields={}).from_dict(data)
+    assert struct_pyd_from_dict.fields == data
+    assert struct_pyd_from_dict.to_dict() == data
+    assert struct_pyd_from_dict.to_json() == data_json
+
+    struct_pyd_from_dict = StructPydantic(fields={}).from_json(data_json)
+    assert struct_pyd_from_dict.fields == data
+    assert struct_pyd_from_dict.to_dict() == data
+    assert struct_pyd_from_dict == struct_pyd_from_dict
+    assert struct_pyd_from_dict.to_json() == data_json