Fix SQLite fetch queries with multiple parameters (#435)

SQLAlchemy 1.4 no longer orders `compiled.bind_names` the same as the sequence of `?` placeholders in the generated SQL. We must iterate keys from `compiled.positiontup` that stores the correct order of bound parameters.

Backport of athenianco#5

Author: vmarkovtsev

databases/backends/sqlite.py

@@ -167,7 +167,9 @@ def _compile(
         args = []
 
         if not isinstance(query, DDLElement):
-            for key, raw_val in compiled.construct_params().items():
+            params = compiled.construct_params()
+            for key in compiled.positiontup:
+                raw_val = params[key]
                 if key in compiled._bind_processors:
                     val = compiled._bind_processors[key](raw_val)
                 else: