Manage release of various iterations of OOO in Mimir 2.5 and 2.6

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Is your feature request related to a problem? Please describe.

Mimir 2.2.0 included the ability to ingest out-of-order samples. That iteration used a boolean OutOfOrder on the BlockMeta struct to indicate that a particular block included out-of-order samples in the mimir-prometheus fork of Prometheus. The upstream version of out-of-order uses a different mechanism to indicate a block has out-of-order samples: a compaction hint on the BlockMetaCompaction.

Describe the solution you'd like

The current version of mimir-prometheus vendored in Mimir (which will end up in Mimir 2.5) uses both of these mechanisms to determine if a block has out-of-order samples. We should do at least one release of Mimir (2.5) with the ability to use both mechanisms before removing the OutOfOrder bool on BlockMeta and using only the upstream Prometheus mechanism in Mimir 2.6

See #3175 #3261 grafana/mimir-prometheus#337