Improve scheduling blaze reminders based on fetched campaigns

[irfano]

Part of #13477

We should detect the changes on the fetched campaigns and avoid scheduling a reminder if there are no changes in the campaign list. For further discussion: p1725970107043749/1725903622.524529-slack-C03L1NF1EA3

[dangermattic]

🚫 Please add a type label (e.g. type: enhancement) and a feature label (e.g. feature: stats) to this issue.