Improve query for unique app metrics

[raymondjacobson]

New supports

# Get all apps
curl "http://localhost:1323/v1/metrics/aggregates/apps/month/unique?bucket_size=day"

# Get data for a specific app by identifier (api_key or app_name as stored)
curl "http://localhost:1323/v1/metrics/aggregates/apps/month/unique?bucket_size=day&app_name=ray"

# Get daily data for last 30 days for a specific app
curl "http://localhost:1323/v1/metrics/aggregates/apps/month/unique?bucket_size=day&app_name=ray"

[dylanjeffers]

Sg