Use udev flags in the rules and cleanup the rules:

Use udev flags in the rules and cleanup the rules:
 - remove default permissions set in 95-dm-notify.rules (and add a hint in 12-dm-permissions.rules to set it by the user directly)
 - add multipath DM_ACTION=="PATH_FAILED" filter
 - remove unnecessary filters in the headers of the rules (we can simply use DM_UDEV_RULES_VSN instead)
 - fix symlink priorities in /dev/disk/ (snapshot volumes have low priority for FS UUID symlinks so it will not overwrite symlinks for the origin)