Add inspection to move the variable declaration into when

#KT-29001 Fixed

idea/testData/inspectionsLocal/moveVariableDeclarationIntoWhen/simple.kt.after

@@ -0,0 +1,8 @@
+fun test() = 42
+
+fun foo() {
+    when (val a = test()) {
+        1 -> a
+        else -> 24
+    }
+}