Store gateway instance limits are under -blocks-storage.bucket-store

[justinjung04]

Is your feature request related to a problem? Please describe. The configs under-blocks-storage.bucket-store are meant to be shared between querier and store-gateways to make sure they are in-sync about what blocks could be found where. However, it currently contains the following store-gateway instance limits:

• -blocks-storage.bucket-store.max-concurrent
• -blocks-storage.bucket-store.max-inflight-requests
• -blocks-storage.bucket-store.max-chunk-pool-bytes

There could also be other configs that are only specific to store-gateway, and it's confusing that they're still part of this shared config.

Describe the solution you'd like Configurations that only apply to store-gateways should be part of -store-gateway