[TASK] (supernova): Remove Silences Worker and Introduce React Query

[ArtieReus]

Description

Replace the silences worker with React Query while maintaining the existing functionality without modifying the store and other components. This refactor is a preparatory step for a future rearchitecture.

Steps

1. Remove Silences Worker

   • Remove the current implementation of the silences worker used for fetching data.

2. Introduce React Query

   • Use React Query to fetch alerts data.
   • Ensure the fetching logic retains the same interval as the alerts worker.

3. Migrate Alert Worker Logic to React Query

   • Transfer the logic from the worker function into the React Query fetching promise.
   • Ensure the fetched data structure matches the existing structure used in the application.

4. Save Fetching Results

   • Save the results fetched by React Query into the Zustand store.
   • Maintain compatibility with the existing store structure and ensure no changes are required in other components.

Acceptance Criteria

• The silences worker is fully removed.
• React Query is successfully integrated for fetching silences data.
• The fetching interval remains consistent with the worker's behavior.
• The results fetched by React Query match the existing data structure and are stored in the Zustand store.
• All existing components relying on the Zustand store remain functional without modification.

Related to

• [EPIC](supernova): Supernova Re-architecture #621

Notes

• This refactor does not introduce new functionality, such as filtering, but sets the groundwork for such changes in a subsequent iteration.