Added one-time payments under "payments" for filtering

[ronaldlangeveld]

ref PLG-153

• Scoped one-time payments (donation_event) under the "payments" category in the member activity feed filter.
• Updated toggleEventType logic to ensure that toggling "payments" also toggles one-time payments when the tipsAndDonations feature is enabled.
• Refactored event type handling into utility functions for easier testing.
• Added unit tests for the new utility functions to ensure correct behaviour.
• Added acceptance testing.