[Store][NotificationsCache] Fixing issues that caused some cache errors

- Remove primary key
- make sure that the id is per room not per event to have no issues with the order that select returned
- Add asserts to detect any null values when testing
- up the db version as the schema changed

Took 16 minutes

lib/src/Store.dart

@@ -55,7 +55,7 @@ class Store {
   _init() async {
     var databasePath = await getDatabasesPath();
     String path = p.join(databasePath, "FluffyMatrix.db");
-    _db = await openDatabase(path, version: 11,
+    _db = await openDatabase(path, version: 12,
         onCreate: (Database db, int version) async {
       await createTables(db);
     }, onUpgrade: (Database db, int oldVersion, int newVersion) async {
@@ -665,19 +665,27 @@ class Store {
   }
 
   Future forgetNotification(String roomID) async {
+    assert(roomID != "");
     await db
         .rawDelete("DELETE FROM NotificationsCache WHERE chat_id=?", [roomID]);
     return;
   }
 
   Future addNotification(String roomID, String event_id, int uniqueID) async {
-    await db.rawInsert("INSERT INTO NotificationsCache VALUES (?, ?,?)",
+    assert(roomID != "");
+    assert(event_id != "");
+    assert(uniqueID != "");
+    await db.rawInsert(
+        "INSERT INTO NotificationsCache(id, chat_id, event_id) VALUES (?, ?, ?)",
         [uniqueID, roomID, event_id]);
+    // Make sure we got the same unique ID everywhere
+    await db.rawUpdate("UPDATE NotificationsCache SET id=? WHERE chat_id=?", [uniqueID, roomID]);
     return;
   }
 
   Future<List<Map<String, dynamic>>> getNotificationByRoom(
       String room_id) async {
+    assert(room_id != "");
     List<Map<String, dynamic>> res = await db.rawQuery(
         "SELECT * FROM NotificationsCache WHERE chat_id=?", [room_id]);
     if (res.length == 0) return null;
@@ -766,7 +774,7 @@ class Store {
 
     /// The database scheme for the NotificationsCache class.
     "NotificationsCache": 'CREATE TABLE IF NOT EXISTS NotificationsCache(' +
-        'id int PRIMARY KEY, ' +
+        'id int, ' +
         'chat_id TEXT, ' + // The chat id
         'event_id TEXT, ' + // The matrix id of the Event
         'UNIQUE(event_id))',