* ECATT: remove dynamic method calls
This commit introduces two new interfaces to remove dynamic method calls.
- ZIF_ABAPGIT_ECATT_DOWNLOAD
- ZIF_ABAPGIT_ECATT_UPLOAD
* ECATT: Rename method
Rename method z_set_stream_for_upload to set_stream_for_upload
as we now use our own interface and there's no risk that SAP
standard introduces a method with the same name
