Modify paths for vendored crates and use --offline configuration

[Blast545]

Changes:

• if the crate being build includes debian/vendor (meaning included vendored crates), we also include a section in the configuration to replace crates.io with local vendored source.
• printf '\n[net]\noffline = true\n' >> pallet-patcher.toml -> Configure cargo to build offline. It won't stop build.rs scripts and other macros, but this keeps ros_buildfarm current behavior.
• Moves vendored crates from debian/vendor to vendor (cp -a debian/vendor "$$TARGET/vendor") when these are installed. They can't be kept in debian because that folder is used for packaging metadata.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

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  Files             ?       57           
  Lines             ?     6985           
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  Hits              ?     3651           
  Misses            ?     2986           
  Partials          ?      348           

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