[loki-distributed] Add querier topologySpreadConstraints

[alexandre1984rj]

Add support Pod Topology Spread Constraints to work with existing affinity since it is being usend through the ksonnet production config.

When new queriers are created, they need to be scheduled into different nodes. If there are not enough nodes in the cluster, new nodes need to be provisioned. This has costs and latency implications and we need to use Kubernetes's TopologySpreadConstraints to evenly spread queriers across the available nodes, but allows more than one querier to be scheduled into the same node.

[CLAassistant]

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