[Guardrails] Rebalance-out shouldn't be allowed after hitting the max data per node per bucket guardrail

Steps:

1. Initialise a 3 node cluster running just the KV service.
2. Configure magmaMaximum=0.0016 in http://172.23.106.242:8091/settings/resourceManagement

3. {"bucket":{"collectionsPerQuota":{"enabled":true,"maximum":1},"dataSizePerNode":{"couchstoreMaximum":1.6,"enabled":true,"magmaMaximum":0.0016},"residentRatio":{"couchstoreMinimum":10,"enabled":true,"magmaMinimum":1}},"coresPerBucket":{"enabled":true,"minimum":0.4},"diskUsage":{"enabled":true,"maximum":85}}

1. Create a Magma bucket with 256 MB RAM per node.
2. Load data until it would hit the max data per node per bucket guardrail.
3. Validated the above by inserting a few documents after hitting the guardrail and received the error 'BUCKET_DATA_SIZE_TOO_BIG'.
4. Rebalance-out a node from the cluster.
5. The rebalance-out operation was allowed and it completed successfully.
6. After rebalance-out, the bucket data on the 2 nodes were 2465825479 and 2452661322 bytes, which is more than the configured guardrail limit. This was fetched from this stat kv_logical_data_size_bytes{state="active"}
7. Hence, the rebalance-out operation shouldn't be allowed.