Implement Unwrap/Remove for conditionals and loops

idea/testData/codeInsight/unwrapAndRemove/unwrapElse/elseCompoundInBlock.kt

@@ -0,0 +1,12 @@
+// OPTION: 3
+fun foo(n: Int): Int {
+    if (n > 0) {
+        println("> 0")
+        n + 10
+    } <caret>else {
+        println("<= 0")
+        n - 10
+    }
+
+    return n
+}

idea/testData/codeInsight/unwrapAndRemove/unwrapElse/elseCompoundInBlock.kt.after

@@ -0,0 +1,7 @@
+// OPTION: 3
+fun foo(n: Int): Int {
+    println("<= 0")
+    n - 10<caret>
+
+    return n
+}

idea/testData/codeInsight/unwrapAndRemove/unwrapElse/elseCompoundInReturn.kt

@@ -0,0 +1,10 @@
+// IS_APPLICABLE: false
+fun foo(n: Int): Int {
+    return if (n > 0) {
+        println("> 0")
+        n + 10
+    } <caret>else {
+        println("<= 0")
+        n - 10
+    }
+}

idea/testData/codeInsight/unwrapAndRemove/unwrapElse/elseSimpleInReturn.kt

@@ -0,0 +1,8 @@
+// OPTION: 2
+fun foo(n: Int): Int {
+    return if (n > 0) {
+        n + 10
+    } <caret>else {
+        n - 10
+    }
+}

idea/testData/codeInsight/unwrapAndRemove/unwrapElse/elseSimpleInReturn.kt.after

@@ -0,0 +1,4 @@
+// OPTION: 2
+fun foo(n: Int): Int {
+    return n - 10<caret>
+}