Cleanup blocks storage config

[pracucci]

What this PR does:
When we introduced the blocks store support to jsonnet we picked the easiest path: define a genericBlocksStorageConfig and set all CLI flags there. These flags were applied to all Cortex services accessing the storage (ingester, querier, ruler, store-gateway, compactor).

However, not all flags we set in genericBlocksStorageConfig are used by all Cortex services. For example, the flag with prefix -blocks-storage.tsdb. are ingester specific.

In this PR I'm cleaning up the config, setting each CLI flag (related to blocks storage) only to Cortex services that actually use it.

Which issue(s) this PR fixes:
N/A

Checklist

• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[pstibrany]

LGTM.

$._config.queryBlocksStorageConfig, $.blocks_metadata_caching_config and $.bucket_index_config seem to be always used together. Maybe the latter two could be merged into first one?

[pracucci]

$._config.queryBlocksStorageConfig, $.blocks_metadata_caching_config and $.bucket_index_config seem to be always used together. Maybe the latter two could be merged into first one?

Ok. Let me do it in a separate PR.