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/FunctionFromAnotherPackage/FunctionFromAnotherPackage.kt

@@ -0,0 +1,8 @@
+package p1
+
+fun test(s: String, i: Int) {
+    p2.foo(<caret>)
+
+fun foo(i: Int) = i
+
+// EXIST: s

idea/idea-completion/testData/smartMultiFile/FunctionFromAnotherPackage/Package.kt

@@ -0,0 +1,3 @@
+package p2
+
+fun foo(s: String) {}