Extract 'test-generator' module out of 'generators'

Also avoid using intellij API where kotlin-stdlib can be used instead

generators/test-generator/build.gradle.kts

@@ -0,0 +1,17 @@
+
+apply { plugin("kotlin") }
+
+dependencies {
+    testCompile(project(":core:util.runtime"))
+    testCompile(projectTests(":compiler:tests-common"))
+    testCompile(projectDist(":kotlin-stdlib"))
+    testCompile(commonDep("junit:junit"))
+    testCompile(ideaSdkDeps("util"))
+}
+
+sourceSets {
+    "main" { }
+    "test" { projectDefault() }
+}
+
+testsJar {}