Query staging data

[trueleo]

Fixes #445.

Description

Implements and makes use of a custom query table provider which combines ListingTable and MemTable for querying remote data and staging data together.

UnionExec is used to combine two inputs together. This can be switched out for SortPreservingMergeExec if output is interleaving staging and remote data together on something like select * from table

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This PR has:

• been tested to ensure log ingestion and log query works.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.