KJS: write minification's test results to separate directory

It allows excluding this directory from indexing inside IDEA
and probably simplifies the main workflow.

js/js.translator/testData/multiModuleOrder/umd.kt

@@ -0,0 +1,16 @@
+// MODULE: lib
+// FILE: lib.kt
+// MODULE_KIND: UMD
+package lib
+
+fun bar() = "OK"
+
+
+// MODULE: main(lib)
+// FILE: main.kt
+// MODULE_KIND: UMD
+package foo
+
+import lib.bar
+
+fun box() = bar()