Update TWAP responses, to make errors for incorrect error in time range, exposed in response

[ValarDragon]

Background

We want the marker for 'potentially unsafe result' to be exposed in the query response. A go API error won't get threaded through to cosmwasm, so this data has to be in the query response field.

Suggested Design

Add a bool field for "is response unstable" to the twap queries, at the GRPC proto layer, and a test for this threading through correctly

Acceptance Criteria

[hieuvubk]

@ValarDragon could pls add more details? Like the return condition of variable

[czarcas7ic]

Believe this is addressed by spot price error that occurs when querying now