Implement reset strategies

[SergioGasquez]

PR based on @jessebraham work in #344, I didn't rebase because there were a lot of conflicts and wanted to manually review the changes while comparing them with esptool.

There are only some small differences:

• Updated classic reset function
• Added some debug logs to better debug similar errors in the future
• Use libc instead of nix crate in set_dtr_rts
  • This was the main reason why #344 was not working as the tiocmset was returning an error.

Related issues/PRs: https://github.com/esp-rs/espflash/issues/349, https://github.com/esp-rs/espflash/pull/344, https://github.com/esp-rs/espflash/issues/323, https://github.com/esp-rs/espflash/issues/394, https://github.com/esp-rs/espflash/pull/387

Maybe related: https://github.com/esp-rs/espflash/issues/442, https://github.com/esp-rs/espflash/issues/450

~Draft PR until some affected user can verify that it's working~ @georgik did some testing and confirmed that it's working!