Add "Control flow with empty body" inspection

#KT-30970 Fixed

idea/testData/inspectionsLocal/controlFlowWithEmptyBody/if/blockHasElse.kt

@@ -0,0 +1,10 @@
+// PROBLEM: 'if' has empty body
+// FIX: none
+
+fun test(i: Int) {
+    <caret>if (i == 1) {
+    } else if (i == 2) {
+    } else if (i == 3) {
+    } else {
+    }
+}