fix: propagate compile errors from imported modules and update test runner to skip them

test/language/module/compile_error/compile_error.wren

@@ -0,0 +1,2 @@
+System.print("before") // expect: before
+import "module" for Module // expect runtime error: Could not compile module 'module'.

test/language/module/compile_error/module.wren

@@ -0,0 +1,2 @@
+// nontest
+undefined

test/language/module/unknown_module.wren

@@ -1 +1 @@
-import "does_not_exist" for DoesNotExist // expect runtime error: Could not find module 'does_not_exist'.
+import "does_not_exist" for DoesNotExist // expect runtime error: Could not load module 'does_not_exist'.