Create v2 QueryService

[yurishkuro]

The components of /cmd/query all depend on a QueryService which is a higher level abstraction that spanstore.Reader as it performs post-query adjustments on the trace before it is returned to the client.

In order to upgrade all the components in query to V2 Storage API we need to create a QueryServiceV2 that will operate on OTLP data instead of legacy model.Span.

The proposal is:

• clone QueryService and update to OTLP data model
• change query app to instantiate both of these structs temporarily
• then we can start upgrading the endpoint handlers to work with QueryServiceV2, starting with apiv3 handler which already operates on OTLP and thus would require minimal changes