feat: added CRUD operations for timers, created decorator for error handling, added schema ; refactor: updated functions and ; test: moved tests from to , written tests for CRUD operations on timers and database.

kawai_focus/tests/json/timer.json

@@ -0,0 +1,5 @@
+{
+    "sound_timer": "alarm-beep.mp3",
+    "zero_time": "00:00:00",
+    "custom_time": "00:00:12"
+}