removes sql alchemy dependency and port parts of URL class

dlt/common/configuration/specs/connection_string_credentials.py

@@ -1,5 +1,5 @@
 from typing import Any, ClassVar, Dict, List, Optional
-from sqlalchemy.engine import URL, make_url
+from dlt.common.libs.sql_alchemy import URL, make_url
 from dlt.common.configuration.specs.exceptions import InvalidConnectionString
 
 from dlt.common.typing import TSecretValue
@@ -26,7 +26,7 @@ def parse_native_representation(self, native_value: Any) -> None:
             # update only values that are not None
             self.update({k: v for k, v in url._asdict().items() if v is not None})
             if self.query is not None:
-                self.query = dict(self.query)
+                self.query = self.query.copy()
         except Exception:
             raise InvalidConnectionString(self.__class__, native_value, self.drivername)
 

dlt/common/configuration/utils.py

@@ -85,6 +85,7 @@ def serialize_value(value: Any) -> Any:
         return str(value)
     if isinstance(value, BaseConfiguration):
         try:
+            print("TO NATIVE")
             return value.to_native_representation()
         except NotImplementedError:
             # no native representation: use dict