NotificationManager.h: Reorder notification struct fields to allow easier creation. (InfiniTimeOrg#1774)

This commit changes the order for the notification struct fields to allow the creation of notifications using a string literal.
```cpp
NotificationManager::Notifiation notification {
  "String literal with notification text",
  42,
  NotificationManager::Categories::SimpleAlert
};
```

Co-authored-by: minacode <[email protected]>

Author: minacode

src/components/ble/NotificationManager.h

@@ -27,11 +27,12 @@ namespace Pinetime {
       struct Notification {
         using Id = uint8_t;
         using Idx = uint8_t;
-        Id id = 0;
-        bool valid = false;
-        uint8_t size;
+
         std::array<char, MessageSize + 1> message;
+        uint8_t size;
         Categories category = Categories::Unknown;
+        Id id = 0;
+        bool valid = false;
 
         const char* Message() const;
         const char* Title() const;