Version 2.0.0

Extensive rework of the crate to cleanup, refactor, and modernize the library and add some new features like CAN FD support.

• Moved to Rust Edition 2021 w/ MSRV 1.64
• Refactored frames into differnt types: Data, Remote, Error (and now FD), that can be managed through enumeraed wraper types CanFrame and/or CanFdFrame
• Pushed some implementation upsream to the libc and nix crates, and/or adapted upstream types.
  • CAN 2.0 frames based on libc::can_frame
  • CAN FD frames based on libc::canfd_frame
• #33 Netlink extensions
  • Creating and deleting interfaces
  • Setting MTU (to/from FD)
• #21 New CI using GitHub Actions
• #20 Composite PR with some modernization
  • Pulls in #13, and updates to the latest neli v0.6
  • Updates nix dependency to latest v0.23
  • Moves to Rust 2018 w/ MSRV 1.54
  • Errors conform to std::error::Error
• #16 Add CAN FD support
• #24 Embedded HAL Traits
  • Plus some source refactoring into more coherent modules