Add btrfs snapshot submenu and move grub2-probe to tools-minimal
The btrfs snapshot submenu was removed because it broke the old grubby tool
since it searched for "menuentry". But now that a BLS config is supported,
this can be added again as long as grubby isn't used.
This patch also moves the grub2-probe tool to the tools-minimal package to
prevent a circular dependency since the grub2-tools package depends on the
os-prober package, but os-prober package needs grub2-probe as a dependency.
So instead of making os-prober to depend on grub2-tools, it can be made to
depend on the grub2-tools-minimal subpackage.
Signed-off-by: Javier Martinez Canillas <firstname.lastname@example.org>