Created module idea-test-framework and moved classes needed for idea tests there

Moved tests for completion and their test data into module idea-completion

idea/idea-completion/testData/smartMultiFile/GenericInheritors1/JavaInheritors.java

@@ -0,0 +1,6 @@
+import p.*
+
+class JavaInheritor1 implements KotlinTrait<I1, I2>{}
+
+// is not suitable because type arguments do not match
+class JavaInheritor2 implements KotlinTrait<I1, I3>{}