[RUST] complete rust implementation

• split code into:
  • lib.rs (library)
  • err.rs (SysdataError)
  • cli.rs (clap configuration)
  • conf.rs (parsing of config file)
  • main.rs (main program logic)
  • tests.rs (some unit tests)
• finish implementing commands
• correctly compute crc32
• apply hints from cargo clippy
• minimize writes by duplicating the table in memory after reading and then comparing the two copies; avoid writing if the two copies remain identical
• implement parsing of configuration file that contains a list of device files and their offsets

CLEAOS-460