Move all basic completion tests to common folder

idea/testData/completion/basic/common/InClassPropertyAccessor.kt

@@ -0,0 +1,9 @@
+class Test(val testParam : Int) {
+  val x : Int get() {
+      val test = 12
+      return te<caret>
+  }
+}
+
+// EXIST: test
+// EXIST: testParam