fix(sharding): apply offset to both from and through in shard request

[ashwanthgoli]

What this PR does / why we need it:

We are applying offset only on From which results in the shard resolver to incorrectly get shards over a long range from-offset-interval -> through for large offsets causing the query to fail with the following error. This pr applies offset on Through as well for the bounded sharding strategy. power of two strategy is already applying it

shard query is too large to execute on a single querier

Which issue(s) this PR fixes:
Fixes #

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Checklist

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• Documentation added
• Tests updated
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[owen-d]

LGTM, nice catch. Small nit: this is probably a good opportunity to refactor the code a bit to use a testable shardsRequestsFor function which encapsulates this adjusted bounds logic.