Add size limits for bulk updates in notification preferences

## Context
Currently, there is no limit on the number of preferences that can be updated in a single bulk update request. This could potentially lead to performance issues with large payloads.

## Proposed Enhancement
Add a maximum limit to the number of preferences that can be updated in a single request to prevent potential performance issues.

## Implementation Details
- Add validation in the bulk update endpoint to limit the number of preferences to 100 per request
- Return appropriate error message when the limit is exceeded

## Related Links
- Pull Request: https://github.com/airqo-platform/AirQo-api/pull/4204
- Discussion: https://github.com/airqo-platform/AirQo-api/pull/4204#discussion_r1921239201

## Additional Notes
This enhancement will help prevent potential performance issues and ensure the API remains stable under load.

/cc @Baalmart