feat(CosmosStore.Linq): Indexed Queries

[bartelink]

NOTE: published as 4.1.0-alpha.16; ideally want to do some more API surface changes before release, but if it mattered to someone that the builds are badged alpha, could do a RC of CosmosStore 4.1

• Adds a CosmosStore.Linq namespace that facilitates efficient querying against Indexes (Uncompressed unfolds stored in Tip documents)
• eqx: Adds top and destroy subcommands
• eqx dump: Applies a bare mode when in -Quiet mode

NOTES:

• use AccessStrategy.Custom mode to store one or more uncompressed unfold(s) alongside a snapshot
• filtering efficiently requires the u[].d.* fields to be indexed (eqx init --indexunfolds)
• sorting requires the u[].d.* fields to be indexed (and uncompressed) (eqx init --indexunfolds)
• render by querying c.u (and using CosmosStoreCategory.TryLoad) (mode: ReadOnly)
• render identity info derived from the StreamName by also retrieving c.p (mode: SnapWithStream)
• transact against the state by querying c._etag, c.u (and using CosmosStoreCategory.TryHydrateTip) (mode: ReadOnly)
• render based on the state and/or id per item by querying c.u[0].d (efficient retrieval as the snapshot will be compressed), and, optionally, c.p (this PR)
• transact based on c._etag and c.u[0].d (this PR)