Performance Metrics & Hot Tier upgrade

📈 Relevant performance metrics

We have revamped the cluster performance metrics with only the metrics that matter:

1. Throughput - How many requests are received on the read/write path?
2. Latency - P99 of the requests received on the read/write path
3. Errors - How many requests resulted in 5xx on the read/write path?

This helps get a high-level overview of the Levitate read-write paths in real-time and from a trend exploration point of view.

🔥 6 months of storage for Hot Tier

All Hot tiers are now upgraded to 6 months of storage by default. Migration for existing clusters is already done.