Add VH-109 Firmware Checksum

[wowkster]

Is your feature request related to a problem? Please describe.
The 2025 release includes a download for the VH-109 firmware but does not include the checksum required to upgrade the firmware using the VH-109 web configuration interface

Describe the solution you'd like
Add the checksum as an available download

[JamieSinn]

I'm working with Kiet on making this a hosted file that Vivid will provide instead of a static flat file we need to host in the repo.