Extraction Engine: Generate function/property accessor with expression body (whenever applicable)

#KT-6405 Fixed

idea/testData/refactoring/extractFunction/controlFlow/throws/evalExpressionWithThrow.kt.after

@@ -11,6 +11,4 @@ fun foo(a: Int): Int {
     return t
 }
 
-private fun i(a: Int, b: Int): Int {
-    return if (a > 0) throw Exception("") else a + b
-}
+private fun i(a: Int, b: Int) = if (a > 0) throw Exception("") else a + b