WX-757 Fix stdout, stderr in workflow body causing crashes (#7386)

Author: aednichols

centaur/src/main/resources/standardTestCases/failures/stderr_stdout_workflow_body/stderr_stdout_workflow_body.wdl

@@ -0,0 +1,8 @@
+version 1.0
+
+workflow break_with_stderr {
+
+  output {
+    File load_data_csv = select_first([stdout(), stderr()])
+  }
+}

centaur/src/main/resources/standardTestCases/stderr_stdout_workflow_body.test

@@ -0,0 +1,13 @@
+name: stderr_stdout_workflow_body
+testFormat: workflowfailure
+
+files {
+  workflow: failures/stderr_stdout_workflow_body/stderr_stdout_workflow_body.wdl
+}
+
+metadata {
+  workflowName: break_with_stderr
+  status: Failed
+  "failures.0.message": "Workflow failed"
+  "failures.0.causedBy.0.message": "Failed to evaluate 'break_with_stderr.load_data_csv' (reason 1 of 2): Evaluating select_first([stdout(), stderr()]) failed: stdout is not implemented at the workflow level, Failed to evaluate 'break_with_stderr.load_data_csv' (reason 2 of 2): Evaluating select_first([stdout(), stderr()]) failed: stderr is not implemented at the workflow level"
+}

wdl/transforms/new-base/src/main/scala/wdl/transforms/base/linking/expression/values/EngineFunctionEvaluators.scala

@@ -51,7 +51,7 @@ object EngineFunctionEvaluators {
                                ioFunctionSet: IoFunctionSet,
                                forCommandInstantiationOptions: Option[ForCommandInstantiationOptions]
     )(implicit expressionValueEvaluator: ValueEvaluator[ExpressionElement]): ErrorOr[EvaluatedValue[WomSingleFile]] =
-      EvaluatedValue(WomSingleFile(ioFunctionSet.pathFunctions.stdout), Seq.empty).validNel
+      ErrorOr(EvaluatedValue(WomSingleFile(ioFunctionSet.pathFunctions.stdout), Seq.empty))
   }
 
   implicit val stderrFunctionEvaluator: ValueEvaluator[StderrElement.type] = new ValueEvaluator[StderrElement.type] {
@@ -60,7 +60,7 @@ object EngineFunctionEvaluators {
                                ioFunctionSet: IoFunctionSet,
                                forCommandInstantiationOptions: Option[ForCommandInstantiationOptions]
     )(implicit expressionValueEvaluator: ValueEvaluator[ExpressionElement]): ErrorOr[EvaluatedValue[WomSingleFile]] =
-      EvaluatedValue(WomSingleFile(ioFunctionSet.pathFunctions.stderr), Seq.empty).validNel
+      ErrorOr(EvaluatedValue(WomSingleFile(ioFunctionSet.pathFunctions.stderr), Seq.empty))
   }
 
   private val ReadWaitTimeout = 60.seconds