Migrate HAL FS module to edge-node

[mattgeddes]

The partially-implemented installer currently uses a Rust crate that's a wrapper around the libblkid library. This causes all kinds of dependency issues when trying to build the Rust code for HolOS. Mainly around the cross compile to statically link, and that buildroot doesn't handle the Rust/Cargo flags to build against buildroot-host libraries.

Instead, we can pull the FS module from the HAL code in holo-host, which does the filesystem label parsing we need. This works because that code supports VFAT and ext[234]. We need ext4 filesystem support, and can add the ISO9660 support for reading the label.