Drop syn proc & quote dep & other id128 refactor

[vilgotf]

• Drop the syn, proc & quote deps by removing the derive feature from serde & manually impl Error instead of with thiserror
• Id128
  • deprecate try_from_slice in favour of TryFrom<[u8]>
  • deprecate parse_str in favor of FromStr
  • add Id128::from_boot method
  • deprecate get_machine in favor of Id128::from_machine
  • deprecate get_machine_app_specific since it goes against the rust API guidelines (users should call Id128::from_machine()?.app_specific() instead)
  • add as_bytes method
  • impl AsRef<[u8]>, AsRef<OsStr>, From<[u8; 16]>, Copy, Default & Hash
  • added serde test
• change all deps versions from ^x.y.z to x.y.z as cargo interprets them the same

This PR is to the best of my knowledge backwards compatible

Closes #78

[lucab]

Thanks for the PR. I think it is generally nice, but at the same time I think it got a bit out of hand and dragged in a lot of misc stuff. I'd suggest to unpack this into multiple commits/PRs so we can separately cover what to land and what to rework.