Decouple core Yaak logic from Tauri (#354)

crates/yaak-common/src/serde.rs

@@ -0,0 +1,23 @@
+use serde_json::Value;
+use std::collections::BTreeMap;
+
+pub fn get_bool(v: &Value, key: &str, fallback: bool) -> bool {
+    match v.get(key) {
+        None => fallback,
+        Some(v) => v.as_bool().unwrap_or(fallback),
+    }
+}
+
+pub fn get_str<'a>(v: &'a Value, key: &str) -> &'a str {
+    match v.get(key) {
+        None => "",
+        Some(v) => v.as_str().unwrap_or_default(),
+    }
+}
+
+pub fn get_str_map<'a>(v: &'a BTreeMap<String, Value>, key: &str) -> &'a str {
+    match v.get(key) {
+        None => "",
+        Some(v) => v.as_str().unwrap_or_default(),
+    }
+}