Rust firmware tools: rflasher and rem100

After the serprog adventures with Embassy on microcontrollers, it was time to tackle the host side of firmware tooling. Two tools that come up constantly in firmware development are flashprog for reading and writing SPI flash chips, and the Dediprog EM100Pro tool for controlling the EM100 SPI flash emulator. Both are C tools that have been around for a while. We ported both to Rust: rflasher and…