Get overview statistics for Qualtrics survey data

Returns: - total_participants: Total number of participants - total_approved_participants: Number of participants where status=APPROVED - daily_submission_count: Array of submissions grouped by date - average_daily_submission: Average number of daily submissions - daily_task_fulfillment: Array of task fulfillments grouped by date - average_daily_approved_submission: Average number of daily task fulfillment (approved) - occupations_info: Total and available occupation counts, plus completed occupations updated in the last 7 days - tasks_info: Total tasks count, remaining tasks count, total instances, remaining instances, unavailable instances updated in the last 7 days, and completed tasks updated in the last 7 days - quality: Quality breakdown (approved_high_quality, approved_low_quality, rejected, screened_out, other) - completion_projections: Estimated remaining days (overall average and last 7 days)