Implement "move expression up/down" action handler

idea/testData/codeInsight/moveUpDown/closingBraces/nested/nested1.kt

@@ -0,0 +1,11 @@
+// MOVE: down
+fun foo(n: Int) {
+    if (n > 0) {
+
+    } else {
+
+    }<caret>
+    while (n > 0) {
+
+    }
+}

idea/testData/codeInsight/moveUpDown/closingBraces/nested/nested1.kt.after

@@ -0,0 +1,11 @@
+// MOVE: down
+fun foo(n: Int) {
+    if (n > 0) {
+
+    } else {
+
+        while (n > 0) {
+
+        }
+    }<caret>
+}

idea/testData/codeInsight/moveUpDown/closingBraces/nested/nested2.kt

@@ -0,0 +1,12 @@
+// MOVE: down
+// IS_APPLICABLE: false
+fun foo(n: Int) {
+    if (n > 0) {
+
+    } else {
+
+    }
+    while (n > 0) {
+
+    }<caret>
+}