RLE fix

[mrexodia]

Description

Fixed a bug in the RLE encoding where a $ would be inserted in the packet when encoding 00000000. This happened when implementing the library list which contained a base with zeroes in it.

API Stability

• This PR does not require a breaking API change

Checklist

• Documentation
  • Ensured any public-facing rustdoc formatting looks good (via cargo doc)
  • (if appropriate) Added feature to "Debugging Features" in README.md
• Validation
  • Included output of running examples/armv4t with RUST_LOG=trace + any relevant GDB output under the "Validation" section below
  • Included output of running ./example_no_std/check_size.sh before/after changes under the "Validation" section below
• If implementing a new protocol extension IDET
  • Included a basic sample implementation in examples/armv4t
  • IDET can be optimized out (confirmed via ./example_no_std/check_size.sh)
  • OR implementation requires introducing non-optional binary bloat (please elaborate under "Description")
• If upstreaming an Arch implementation
  • I have tested this code in my project, and to the best of my knowledge, it is working as intended.

Validation

Added tests to make sure both $ and # are not in the RLE packet. Can remove if overkill.

[daniel5151]

I'm astonished this bug has hid itself for so long, hah.

Thanks for sending in this fix (and tests)!