feat(snapshot-manager): migrate snapshot management to Rust

rust/snapshot_manager/tests/fixtures/zfs

@@ -0,0 +1,12 @@
+#!/bin/sh
+if [ -n "${SNAPSHOT_TEST_SCRIPT:-}" ]; then
+  printf '%s\n' "$*" >> calls
+  . "$SNAPSHOT_TEST_SCRIPT"
+  exit
+fi
+
+case "$*" in
+  'list -Hp -t filesystem -o name') printf '%s\n' pool/home ;;
+  'snapshot pool/home@'*) printf '%s\n' 'permission denied' >&2; exit 1 ;;
+  *) exit 99 ;;
+esac