API endpoints should return 404 rather than raising error for badly formed PKs

[sentry-io]

ValueError: badly formed hexadecimal UUID string

Sentry Issue: KOLIBRI-BACKEND-2CX

ValueError: badly formed hexadecimal UUID string
(22 additional frame(s) were not displayed)
...
  File "django/db/models/lookups.py", line 170, in as_sql
    rhs_sql, rhs_params = self.process_rhs(compiler, connection)
  File "django/db/models/lookups.py", line 103, in process_rhs
    return self.get_db_prep_lookup(value, connection)
  File "django/db/models/lookups.py", line 196, in get_db_prep_lookup
    [get_db_prep_value(value, connection, prepared=True)]
  File "morango/models/fields/uuids.py", line 39, in get_db_prep_value
    value = uuid.UUID(value)
  File "uuid.py", line 177, in __init__
    raise ValueError('badly formed hexadecimal UUID string')

[rtibbles]

Fixed in #11009