Logged out users viewing a closed group see an error message instead of redirect to login

[DerekCaelin]

Description

Users who click on a URL to view a closed group (say, a group that someone has shared with them) view a non-human-readable error message. They should instead see a login screen, which would direct them to see the group.

Steps To Reproduce

1. Be logged out
2. Click on URL for closed group: https://app.terraso.org/groups/aldea-terraso-colaboracion
3. See issue

Expected behavior

User should be presented with a login screen. After they log in, they should be redirected to the group (which will either report that it is "closed" and give the user a chance to request entry, or "open" and give the user the option to join.

Actual behavior

The user sees an error message: Oops, something went wrong. Try again in a few minutes. (Error: "%(value)s" is not a valid UUID.