Fix Makefile to make it work for fresh projects

[tizianocitro]

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Description

• make clean and all targets using it would fail without running make setup first. Now it works, as it ignores missing env error.
• Improved clean by removing all cache files.
• Added make destroy to reset the environment.

Checklist

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• Have you written tests to cover all your changes? If not, provide a reason.
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