feat: support compatibility with nanosecond MID precision (phase 1)

[cheb0]

Description

The is the intermediate version for supporting nanosecond MID. This version still operates in millisecond MIDs, but is compatible with the current (main) version as well as with future (phase 2) version where seq.MID contains nanoseconds. This allows us to rollback in case of problem with the future version.

• seq.MID are still in milliseconds.
• New frac version to indicate that seq.MID are in nanoseconds. This version silently converts them to milliseconds
• New metadata version which contains seq.MID in nanoseconds. This version converts them to milliseconds as well.
• New QPR encoding for async version for same reasons.
• Async search info now has version (1 and 2), since it contains seq.MID inside stored JSON. If we see a different version (naonseconds), we convert them to millis and change version.
• Frac cache now omits cached info for fractions if fraction version differs from the current version. This is simple because info contains seq.MID and we can not change versions.
• Support for new seq.ID string representation is added. If MID is in nanoseconds, then delimiter is _ instead of -. In this version, if we see _ delimiter, then we convert to milliseconds.
• Proxy now can work with new (phase 2) and current stores, i.e. can merge millisecond and nanosecond MID responses. There is a GRPC header which every store sends. This means proxy can operate properly even during the deploy/rollback process.

Relates to #232

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 64.41718% with 58 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.73%. Comparing base (990f82d) to head (bfeba1d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
proxy/search/ingestor.go	52.38%	8 Missing and 2 partials ⚠️
seq/seq.go	60.00%	9 Missing and 1 partial ⚠️
proxy/search/async.go	35.71%	8 Missing and 1 partial ⚠️
asyncsearcher/async_searcher.go	14.28%	6 Missing ⚠️
indexer/meta_data.go	25.00%	6 Missing ⚠️
network/grpcutil/interceptors.go	81.81%	2 Missing and 2 partials ⚠️
frac/sealed/block_info.go	0.00%	2 Missing and 1 partial ⚠️
frac/sealed/seqids/blocks.go	0.00%	2 Missing and 1 partial ⚠️
frac/sealed_loader.go	62.50%	1 Missing and 2 partials ⚠️
asyncsearcher/encoding.go	93.75%	1 Missing and 1 partial ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #248      +/-   ##
==========================================
- Coverage   71.88%   71.73%   -0.16%     
==========================================
  Files         199      199              
  Lines       14570    14700     +130     
==========================================
+ Hits        10474    10545      +71     
- Misses       3362     3412      +50     
- Partials      734      743       +9     

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