Library `blockdevice` was extracted as `talos-systems/go-blockdevice`,
this PR finalizes the move by removing Talos copy of it.
Some functions around `mkfs`/`growfs` were extracted as `makefs`
package, as they depend on `cmd` package.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
