Fix most import related mypy errors

jedi/inference/references.py

@@ -5,7 +5,8 @@ from parso import python_bytes_to_unicode
 
 from jedi.debug import dbg
 from jedi.file_io import KnownContentFileIO
-from jedi.inference.imports import SubModuleName, load_module_from_path
+from jedi.inference.names import SubModuleName
+from jedi.inference.imports import load_module_from_path
 from jedi.inference.filters import ParserTreeFilter
 from jedi.inference.gradual.conversion import convert_names