Support CI workflow with specified ROM, FMC, and RT versions

[jhand2]

Revisions of ROM and FMC/RT are spread across different branches/tags. We do not currently have a way to produce a single release which will package binaries at specific revisions (currently our release builds everything from a single commit).

We should be able to build FMC/RT from head, but still bundle ROM for a specific release (e.g. 1.0.1).

This can be a Github workflow which takes as input parameters specific tags/commit hashes at which to build each firmware stage.