test: add setting property tests

Some initial UserSettingsStore property tests

damusTests/damusTests.swift

@@ -79,7 +79,22 @@ class damusTests: XCTestCase {
         XCTAssertNotNil(parsed[1].is_url)
         XCTAssertNotNil(parsed[2].is_text)
     }
-    
+
+    func testStringArrayStorage() {
+        let key = "test_key_string_values"
+        let scoped_key = setting_property_key(key: key)
+
+        let res = setting_set_property_value(scoped_key: scoped_key, old_value: [], new_value: ["a"])
+        XCTAssertEqual(res, ["a"])
+
+        let got = setting_get_property_value(key: key, scoped_key: scoped_key, default_value: [String]())
+        XCTAssertEqual(got, ["a"])
+
+        _ = setting_set_property_value(scoped_key: scoped_key, old_value: got, new_value: ["a", "b", "c"])
+        let got2 = setting_get_property_value(key: key, scoped_key: scoped_key, default_value: [String]())
+        XCTAssertEqual(got2, ["a", "b", "c"])
+    }
+
     func testParseUrlUpper() {
         let parsed = parse_note_content(content: "a HTTPS://jb55.COM b", tags: []).blocks