Simplified CodeTransformationTest. Only one doTest method remains, intention class is moved to test data. Merged other intention tests (SpecifyTypeExplicitlyTest, ConvertToBlock/ExpressionBodyTest) into this one.

idea/testData/intentions/convertToExpressionBody/anonymousObjectExpression.kt.after

@@ -0,0 +1,9 @@
+trait I {
+    fun foo(): String
+}
+
+fun bar(): I = object: I {
+    override fun foo(): String {
+        return "a"
+    }
+}