Introduce Variable: Proper occurrence search in generated block expression

#KT-7836 Fixed
 #KT-8443 Fixed
 #EA-71411 Fixed

idea/testData/refactoring/introduceVariable/IntroduceAndCreateBlock.kt

@@ -0,0 +1,3 @@
+fun test(n: Int) {
+    val t = if (n > 0) <selection>n + 1</selection> else n
+}

idea/testData/refactoring/introduceVariable/IntroduceAndCreateBlock.kt.after

@@ -0,0 +1,6 @@
+fun test(n: Int) {
+    val t = if (n > 0) {
+        val i = n + 1
+        i
+    } else n
+}

idea/testData/refactoring/introduceVariable/IntroduceLambdaAndCreateBlock.kt

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun foo(p: Int, list: List<Int>) {
+    if (p > 0) list.filter <selection>{ it > 0 }</selection>
+}

idea/testData/refactoring/introduceVariable/IntroduceLambdaAndCreateBlock.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+
+fun foo(p: Int, list: List<Int>) {
+    if (p > 0) {
+        val function: (Int) -> Boolean = { it > 0 }
+        list.filter(function)
+    }
+}