Go: Add support for provenance pretty-printing as a qltest post-process step

Author: owen-mc

go/ql/test/TestUtilities/PrettyPrintModels.ql

@@ -0,0 +1,18 @@
+/**
+ * @kind test-postprocess
+ */
+
+import codeql.dataflow.test.ProvenancePathGraph
+import semmle.go.dataflow.ExternalFlow
+
+external predicate queryResults(string relation, int row, int column, string data);
+
+external predicate queryRelations(string relation);
+
+query predicate resultRelations(string relation) { queryRelations(relation) }
+
+module Res = TranslateProvenanceResults<interpretModelForTest/2, queryResults/4>;
+
+from string relation, int row, int column, string data
+where Res::results(relation, row, column, data)
+select relation, row, column, data