Ensure timestamp/date returns the same values/format as the extended protocol

Author: pst9354

lib/src/types/text_codec.dart

@@ -255,13 +255,12 @@ class PostgresTextDecoder {
 
       case TypeOid.timestampWithTimezone:
       case TypeOid.timestampWithoutTimezone:
-        return DateTime.parse(di.asText);
-
+        return DateTime.parse('${di.asText}Z');
       case TypeOid.numeric:
         return di.asText;
 
       case TypeOid.date:
-        return DateTime.parse(di.asText);
+        return DateTime.parse('${di.asText}T00:00:00Z');
 
       case TypeOid.json:
       case TypeOid.jsonb: