addrs: AbsModuleCallOutput to ConfigOutputValue translation

The end-goal is to retrieve ConfigOutputValues from References.
This ties in with the work on deprecated outputs.

internal/addrs/module_call.go

@@ -176,6 +176,15 @@ func (m ModuleCallOutput) UniqueKey() UniqueKey {
 
 func (m ModuleCallOutput) uniqueKeySigil() {}
 
+func (m ModuleCallOutput) ConfigOutputValue() ConfigOutputValue {
+	return ConfigOutputValue{
+		Module: Module{m.Call.Name},
+		OutputValue: OutputValue{
+			Name: m.Name,
+		},
+	}
+}
+
 // ModuleCallInstanceOutput is the address of a particular named output produced by
 // an instance of a module call.
 type ModuleCallInstanceOutput struct {
@@ -210,3 +219,24 @@ func (co ModuleCallInstanceOutput) AbsOutputValue(caller ModuleInstance) AbsOutp
 	moduleAddr := co.Call.ModuleInstance(caller)
 	return moduleAddr.OutputValue(co.Name)
 }
+
+type AbsModuleCallOutput struct {
+	Call AbsModuleCall
+	Name string
+}
+
+func (c AbsModuleCall) Output(name string) AbsModuleCallOutput {
+	return AbsModuleCallOutput{
+		Call: c,
+		Name: name,
+	}
+}
+
+func (m AbsModuleCallOutput) ConfigOutputValue() ConfigOutputValue {
+	return ConfigOutputValue{
+		Module: m.Call.StaticModule(),
+		OutputValue: OutputValue{
+			Name: m.Name,
+		},
+	}
+}