Libcoveweb

Changed

- Randomize the uploaded file subdirectory, to allow coves to hide original files from unauthenticated users

Changed

- Switch to Werkzeug from uc-rfc6266-parser
- Drop Python 3.6 support
- Use FieldFile.path instead of File.name, to avoid unclosed file warnings

Add

- Store the original form parameters that were used when submitting the data. Allowing for users of lib-cove-web to create custom actions based on the input.

Removed

- "Tool is Alpha" content from banner block in base template

- Do not warn if `SECRET_KEY` is not set in settings

Fixed

- Include .mo files in the PyPI package

Changed

- Add support to `html_error_msg` for messages about a non-unique combination of multiple IDs. (E.g. ocid and id, as added in [this lib-cove-ocds PR](https://github.com/open-contracting/lib-cove-ocds/pull/91)).
- `.mo` files are commited now, so we don't have to rely on the parent cove project finding them with `compilemessages` https://github.com/open-contracting/deploy/issues/269