[PROD] Notification subscriptions refactor

[szabozoltan69]

Issue

Instead of the recent country ∪ region ∪ disaster type ∪ (emergencies/operations/surge alerts)

we should use the subscriptions this way:

(country ∪ region) ∩ disaster type ∩ (emergencies/operations/surge alerts)

So we should only send the country+region/disaster_type filtered notifications (of the subscribed entities).

[szabozoltan69]

@tovari @mariam-yu – if this logic should be expressed by some new texts, please say it.

[mariam-yu]

@szabozoltan69 what does the icon mean?

[szabozoltan69]

@mariam-yu you mean ∪ and ∩? Union and Intersection.