feat(script): Print warning and exit gracefully if snapshot name would be too long (#1)

pacman-zfs-snapshot.sh

@@ -160,6 +160,10 @@ function find_max_dataset_name_length () {
             max_dataset_name_length="${#dataset_name_no_pkgs}"
         fi
     done
+
+    if [[ "${max_dataset_name_length}" -gt "${max_zfs_snapshot_name_length}" ]]; then
+        pprint 'warn' 'Snapshot name would exceed ZFS '"${max_zfs_snapshot_name_length}"' chars limit. Skipping snapshots ...' '0'
+    fi
 }
 
 function main () {