tfprotov5+tfprotov6: Initial MoveResourceState support (#364)

Reference: #362
Reference: #363

The next version of the plugin protocol (5.5/6.5) includes support for moving resource state. This change introduces the initial implementation of that support including:

- Updated Protocol Buffers definitions
- Re-generated Protocol Buffers Go code
- Initial implementations of `tfprotov5` and `tfprotov6` package abstractions and wiring between those abstractions and the Protocol Buffers generated Go code
- Initial implementations of `tfprotov5/tf5server` and `tfprotov6/tf6server` for the new `MoveResourceState` RPC

This temporarily will not require `ProviderServer` implementations to include `MoveResourceState` implementation, however that change will occur in a subsequent release.

.changes/unreleased/FEATURES-20240112-153355.yaml

@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'tfprotov5+tfprotov6: Upgraded protocols and added types to support the `MoveResourceState`
+  RPC'
+time: 2024-01-12T15:33:55.940212-08:00
+custom:
+  Issue: "364"

.changes/unreleased/NOTES-20240112-153501.yaml

@@ -0,0 +1,6 @@
+kind: NOTES
+body: 'tfprotov5+tfprotov6: An upcoming release will require the MoveResourceState
+  implementation as part of ResourceServer'
+time: 2024-01-12T15:35:01.843365-08:00
+custom:
+  Issue: "364"

tfprotov5/internal/fromproto/resource.go

@@ -42,12 +42,11 @@ func ValidateResourceTypeConfigResponse(in *tfplugin5.ValidateResourceTypeConfig
 
 func UpgradeResourceStateRequest(in *tfplugin5.UpgradeResourceState_Request) (*tfprotov5.UpgradeResourceStateRequest, error) {
 	resp := &tfprotov5.UpgradeResourceStateRequest{
+		RawState: RawState(in.RawState),
 		TypeName: in.TypeName,
 		Version:  in.Version,
 	}
-	if in.RawState != nil {
-		resp.RawState = RawState(in.RawState)
-	}
+
 	return resp, nil
 }
 
@@ -219,3 +218,15 @@ func ImportedResources(in []*tfplugin5.ImportResourceState_ImportedResource) ([]
 	}
 	return resp, nil
 }
+
+func MoveResourceStateRequest(in *tfplugin5.MoveResourceState_Request) (*tfprotov5.MoveResourceStateRequest, error) {
+	resp := &tfprotov5.MoveResourceStateRequest{
+		SourceProviderAddress: in.SourceProviderAddress,
+		SourceSchemaVersion:   in.SourceSchemaVersion,
+		SourceState:           RawState(in.SourceState),
+		SourceTypeName:        in.SourceTypeName,
+		TargetTypeName:        in.TargetTypeName,
+	}
+
+	return resp, nil
+}

tfprotov5/internal/fromproto/server_capabilities.go

@@ -15,6 +15,7 @@ func ServerCapabilities(in *tfplugin5.ServerCapabilities) *tfprotov5.ServerCapab
 
 	return &tfprotov5.ServerCapabilities{
 		GetProviderSchemaOptional: in.GetProviderSchemaOptional,
+		MoveResourceState:         in.MoveResourceState,
 		PlanDestroy:               in.PlanDestroy,
 	}
 }

tfprotov5/internal/fromproto/state.go

@@ -9,6 +9,10 @@ import (
 )
 
 func RawState(in *tfplugin5.RawState) *tfprotov5.RawState {
+	if in == nil {
+		return nil
+	}
+
 	return &tfprotov5.RawState{
 		JSON:    in.Json,
 		Flatmap: in.Flatmap,