added instancesdk.Get() feature and its gRPC API

[ilgooz]

depends on #1074

[NicolasMahe]

Suggested change

	rpc Get (GetInstanceRequest) returns (GetInstanceResponse) {}
	rpc Get (GetInstanceRequest) returns (definition.Instance) {}

I really recommend to directly returning the Instance definition. That's the directly on the new API. Simpler is better.
Check:

engine/protobuf/api/execution.proto

Lines 9 to 15 in acc3e08

	service Execution {
	// Get returns a single Execution specified in a request.
	rpc Get(GetExecutionRequest) returns (definition.Execution) {}
	// Stream returns a stream of executions that satisfy criteria
	// specified in a request.
	rpc Stream(StreamExecutionRequest) returns (stream definition.Execution) {}

[NicolasMahe]

Also, CreateInstanceResponse should be replaced also by the instance proto definition:

engine/protobuf/api/instance.proto

Lines 15 to 18 in acc3e08

	message CreateInstanceResponse {
	string hash = 1; // Service's instance hash.
	string serviceHash = 2; // Service's bare hash.
	}

monday task: https://mesg.monday.com/boards/231078139/pulses/231079102/posts/361694557

[ilgooz]

I really recommend to directly returning the Instance definition. That's the directly on the new API. Simpler is better.
Check:

engine/protobuf/api/execution.proto

Lines 9 to 15 in acc3e08

	service Execution {
	// Get returns a single Execution specified in a request.
	rpc Get(GetExecutionRequest) returns (definition.Execution) {}
	// Stream returns a stream of executions that satisfy criteria
	// specified in a request.
	rpc Stream(StreamExecutionRequest) returns (stream definition.Execution) {}

I don't agree with this one as discussed before but I can commit the changes as you like, if you prefer that way.

[NicolasMahe]

Let's reach consensus on the forum: https://forum.mesg.com/t/standardisation-of-the-grpc-apis/320

[ilgooz]

Also, CreateInstanceResponse should be replaced also by the instance proto definition:

engine/protobuf/api/instance.proto

Lines 15 to 18 in acc3e08

	message CreateInstanceResponse {
	string hash = 1; // Service's instance hash.
	string serviceHash = 2; // Service's bare hash.
	}

monday task: https://mesg.monday.com/boards/231078139/pulses/231079102/posts/361694557

done