Wrap with let: fix it works correctly for invoking function type

#KT-39182 Fixed

idea/testData/quickfix/wrapWithSafeLetCall/invokeFunctionType.kt

@@ -0,0 +1,10 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+
+interface Foo {
+    val bar: ((Int) -> Unit)?
+}
+
+fun test(foo: Foo) {
+    foo.bar<caret>(1)
+}

idea/testData/quickfix/wrapWithSafeLetCall/invokeFunctionType.kt.after

@@ -0,0 +1,10 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+
+interface Foo {
+    val bar: ((Int) -> Unit)?
+}
+
+fun test(foo: Foo) {
+    foo.bar?.let { it(1) }
+}

idea/testData/quickfix/wrapWithSafeLetCall/invokeFunctionType2.kt

@@ -0,0 +1,10 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+
+interface Foo {
+    val bar: ((Int) -> Unit)?
+}
+
+fun Foo.test() {
+    <caret>bar(1)
+}

idea/testData/quickfix/wrapWithSafeLetCall/invokeFunctionType2.kt.after

@@ -0,0 +1,10 @@
+// "Wrap with '?.let { ... }' call" "true"
+// WITH_RUNTIME
+
+interface Foo {
+    val bar: ((Int) -> Unit)?
+}
+
+fun Foo.test() {
+    bar?.let { it(1) }
+}