[tests] Test cases ensuring correct working of Fuzzy Location feature

[DragnEmperor]

Test cases ensuring correct creation and handling of fuzzy locations based on WHOIS lookup. Test coverage should include:

• Creation of new fuzzy location and updating the same whenever last_ip of device changes.
• Ensuring is_fuzzy is set True/False when auto-generated via task or when manually edited via admin or API respectively.
• Notification is triggered after fuzzy location creation/updated.
• Alert is shown when viewing fuzzy location in the admin interface.
• Behavior when organization.is_fuzzy_enabled=False (no fuzzy location should be created).

Dependencies

• [ ] https://github.com/openwisp/openwisp-controller/issues/1034
• [x] https://github.com/openwisp/openwisp-controller/issues/1035
• [x] https://github.com/openwisp/openwisp-controller/issues/1036