[feature] Fuzzy location creation

[DragnEmperor]

Checklist

• [x] I have read the OpenWISP Contributing Guidelines.
• [ ] I have manually tested the changes proposed in this pull request.
• [ ] I have written new test cases for new code and/or updated existing tests for changes to existing code.
• [ ] I have updated the documentation.

Reference to Existing Issue

Closes #1034.

Description of Changes

Fuzzy locations task is added to allow creation of such locations when WhoIs is created for the same device. Also the task should attach the device to an existing location if already WhoIs is available for that device.

Please describe these changes.