Fix compilation of fields with name identical to their type (#294)

* Revert "Fix compilation of fields named 'bytes' or 'str' (#226)"

This reverts commit deb623ed14.

* Fix compilation of fileds with name identical to their type

* Added test for field-name identical to python type

Co-authored-by: Guy Szweigman <guysz@nvidia.com>

src/betterproto/plugin/models.py

@@ -30,6 +30,7 @@ reference to `A` to `B`'s `fields` attribute.
 """
 
 
+import builtins
 import betterproto
 from betterproto import which_one_of
 from betterproto.casing import sanitize_name
@@ -237,6 +238,7 @@ class OutputTemplate:
     imports: Set[str] = field(default_factory=set)
     datetime_imports: Set[str] = field(default_factory=set)
     typing_imports: Set[str] = field(default_factory=set)
+    builtins_import: bool = False
     messages: List["MessageCompiler"] = field(default_factory=list)
     enums: List["EnumDefinitionCompiler"] = field(default_factory=list)
     services: List["ServiceCompiler"] = field(default_factory=list)
@@ -268,6 +270,8 @@ class OutputTemplate:
         imports = set()
         if any(x for x in self.messages if any(x.deprecated_fields)):
             imports.add("warnings")
+        if self.builtins_import:
+            imports.add("builtins")
         return imports
 
 
@@ -283,6 +287,7 @@ class MessageCompiler(ProtoContentBase):
         default_factory=list
     )
     deprecated: bool = field(default=False, init=False)
+    builtins_types: Set[str] = field(default_factory=set)
 
     def __post_init__(self) -> None:
         # Add message to output file
@@ -376,6 +381,8 @@ class FieldCompiler(MessageCompiler):
         betterproto_field_type = (
             f"betterproto.{self.field_type}_field({self.proto_obj.number}{field_args})"
         )
+        if self.py_name in dir(builtins):
+            self.parent.builtins_types.add(self.py_name)
         return f"{name}{annotations} = {betterproto_field_type}"
 
     @property
@@ -408,9 +415,16 @@ class FieldCompiler(MessageCompiler):
             imports.add("Dict")
         return imports
 
+    @property
+    def use_builtins(self) -> bool:
+        return self.py_type in self.parent.builtins_types or (
+            self.py_type == self.py_name and self.py_name in dir(builtins)
+        )
+
     def add_imports_to(self, output_file: OutputTemplate) -> None:
         output_file.datetime_imports.update(self.datetime_imports)
         output_file.typing_imports.update(self.typing_imports)
+        output_file.builtins_import = output_file.builtins_import or self.use_builtins
 
     @property
     def field_wraps(self) -> Optional[str]:
@@ -504,9 +518,12 @@ class FieldCompiler(MessageCompiler):
 
     @property
     def annotation(self) -> str:
+        py_type = self.py_type
+        if self.use_builtins:
+            py_type = f"builtins.{py_type}"
         if self.repeated:
-            return f"List[{self.py_type}]"
-        return self.py_type
+            return f"List[{py_type}]"
+        return py_type
 
 
 @dataclass