Cache counts on /api/v1/facility/ route

[sainak]

/api/v1/facility/ is causing n+1 quires due to count of beds and patients, to optimize this, instead store the count in redis tasks:

• store count of active patients and beds in redis
• invalidate count when the data changes
• come up with an optimized way or storing count of multiple facilities if it doesnt exists
• make the helper funcions abstract so that they can be used with other fields/models