feat: Scalable Compactor

[cyriltovena]

This PR introduces a scalable compactor component that can split and merge Pyroscope blocks to improve performance and deduplicate replication factor.

This is heavily inspired by Mimir compactor but adapted for Pyroscope. One of the main difference for instance is that Pyroscope maxT are inclusive.

The design and behaviour is documented here https://grafana.com/docs/mimir/latest/references/architecture/components/compactor/

Splitting is optional and only required for large tenants where output blocks would be too big.

Remaining tasks:

• Add the compactor component (right now only the package is there)
• Update the store-gateway to only download compacted blocks and use the block index file.
• Tweak the configuration to fit Pyroscope needs (specially the first range is 2h where our blocks is 3h by default)
• Test in a real environment and iterate on it.
  • Test vertical compaction
  • Test split and merge compaction
• Document operations [DOC] Document the Compactor #2540

Previous related PR:

• Fixes IterBlockMeta to skip dir without meta #2401
• Adds a way to validate local blocks #2397
• block: Adds Download and MarkForNoCompact #2396
• Refactoring: Create a common ring configuration #2391
• Adds bucketindex package #2388
• Adds a tenant scanner #2384
• Introduce a meta fetcher that synchronize filtered metadata locally #2381
• storage: Refactor block compaction to allow shard-splitting #2366
• Correctly setup compaction sources in block meta files #2184
• Fixes compaction incorrect profile seriesRef column #2178
• Fixes a compaction bug in series rewriting #2176
• Compact Blocks #2134
• Fixes a race detected when generating ULID #2467
• Feat: ingest align block ranges. #2521

Testing Result

See how block were before level 1 not aligned, now you can see the 8h range being compacted.

[simonswine]

I have not made it through every line of this PR, but I was able to get it running on a local cluster.

[simonswine]

Thanks for looking at my comments and addressing them (when they were valid 😆) and obviously bringing compaction 🚀

LGTM