Add pagination and unread-only filter options to notifications/all endpoint

[GPortas]

Overview of the Feature Request

The notifications/all endpoint currently does not support pagination, which causes very long response times for users with a large number of notifications. This impacts performance and user experience.

Requirements

Add pagination support to the endpoint to handle large datasets more efficiently.

Add a filter option to return only unread notifications, since those are the ones required by the SPA.

What kind of user is the feature intended for?
API User

What inspired the request?
SPA needs

What existing behavior do you want changed?
None

Any brand new behavior do you want to add to Dataverse?
New optional query parameters to endpoint notifications/all

Are you thinking about creating a pull request for this feature?
Yes