Adding gRPC Client Streaming Example

[coolwednesday]

• This PR adds examples for the current gofr-cli approach to additionally also let user generate gRPC streaming handlers with all the observability features, i.e. logs, metrics, traces.
• This PR can only be merged after merging CLI PR : Adding template to generate grpc streaming code gofr-cli#48
• This PR can be tested after merging server side implementation in the following PR : Adding examples and modifying grpc to add interceptor for streaming #1684
• Currently only the whole client call is being traced and logged. We need to work on adding support for every subsequent call inside, also being traced and logged.