Support Estimate Swap queries via grpc gateway

[mattverse]

Background

GRPC Gateway does not support queries on repeated structs in proto, thus all estimate swaps are not supported in GRPC gateway as of right now, only through GRPC.

Suggested Design

Suggested design is that we leave the current estimate queries as is, since

1. Changing this would be API breaking
2. Using repeated structs in GRPC is a better option for code sanity.

Instead what we can do is create a secondary query for grpc gateway, where we do not use repeated structs. We can do this by using repeated primitive types as fields in the request proto struct and then mapping them by index internally to create the needed repeated struct.

Acceptance Criteria

• New Query to support estimate swap query for grpc gateway has been added and tested