Add WD Cmd for Building + Sending Checked Chunks to Hercules UART

[zCoCo]

Add ability to send chunk to Hercules UART. Based off NetworkManager_SendBgApiCommand.

Sets stage for programming Hercules via WD in a reliable async manner (see #183 ). Would allow for largely plug-and-play use with Radio Passthrough Programming State Machine.

• Add ability for WD to parse (and validate) Fw::IrisByteString args packed by GSW.
• Make checked by FSW CRC32 (like NetworkManager_SendBgApiCommand).
• Add Chunk ID and record keeping (like NetworkManager_SendBgApiCommand).
• Add Record dump command.
• Add ability to build chunk of fixed max size (add idx and len params to cmd) with one command and then trigger send with another.
• Add supporting GSW infra.