Feature mirrors and patterns: preserve replay and add Flip/Center placement (#1619)

Thanks @Karl-VonRichter.

crates/engine/src/cmd/mod.rs

@@ -318,3 +318,15 @@ fn edit_distance(a: &str, b: &str) -> usize {
     }
     row[b.len()]
 }
+
+pub(super) fn alignment_param(p: &Value, key: &str, cmd: &str) -> Result<solidcraft_sketch::PatternAlignment> {
+    p.get(key).map_or(Ok(solidcraft_sketch::PatternAlignment::default()), |value| {
+        serde_json::from_value(value.clone()).map_err(|_| crate::params::bad(cmd, format!("`{key}` must be left, center or right")))
+    })
+}
+
+pub(super) fn reversed_param(p: &Value, key: &str, cmd: &str) -> Result<bool> {
+    p.get(key).map_or(Ok(false), |value| {
+        serde_json::from_value(value.clone()).map_err(|_| crate::params::bad(cmd, format!("`{key}` must be true or false")))
+    })
+}