Parameterize uri resolution and parsing of options, use package:path

lib/protobuf_field.dart

Index: lib/protobuf_field.dart
diff --git a/lib/protobuf_field.dart b/lib/protobuf_field.dart
index 897de78780aaaa0c50208d7c1f93253e6dd5bad7..8b83afda85e447816bc640c60e642b174c51ba93 100644
--- a/lib/protobuf_field.dart
+++ b/lib/protobuf_field.dart
@@ -372,8 +372,8 @@ class ProtobufField {
       }
       return underscoresToCamelCase(name);
     }
-    var name = context.options.fieldNameOption(fqname);
-    return (name != null) ? name : underscoresToCamelCase(_field.name);
+    var name = context.options.fieldNameOverrides[fqname];
+    return name != null ? name : underscoresToCamelCase(_field.name);
   }
 
   int get wireType {