[FIR] Report missing NO_ELSE_IN_WHEN for when statement with expect enums and sealed classes

^KT-59404 Fixed

compiler/testData/diagnostics/tests/multiplatform/exhaustiveness/expectEnum.fir.kt

@@ -8,7 +8,7 @@ expect enum class Base {
 }
 
 fun testCommon(base: Base) {
-    val x = when (base) { // must be an error
+    val x = <!NO_ELSE_IN_WHEN!>when<!> (base) { // must be an error
         Base.A -> 1
         Base.B -> 2
     }

compiler/testData/diagnostics/tests/multiplatform/exhaustiveness/expectSealedClass.fir.kt

@@ -9,7 +9,7 @@ class A : Base()
 object B : Base()
 
 fun testCommon(base: Base) {
-    val x = when (base) { // must be an error
+    val x = <!NO_ELSE_IN_WHEN!>when<!> (base) { // must be an error
         is A -> 1
         B -> 2
     }

compiler/testData/diagnostics/tests/multiplatform/exhaustiveness/expectSealedInterface.fir.kt

@@ -9,7 +9,7 @@ class A : Base
 object B : Base
 
 fun testCommon(base: Base) {
-    val x = when (base) { // must be an error
+    val x = <!NO_ELSE_IN_WHEN!>when<!> (base) { // must be an error
         is A -> 1
         B -> 2
     }

compiler/testData/diagnostics/tests/multiplatform/exhaustiveness/kt45796.fir.kt

@@ -8,7 +8,7 @@ expect sealed class SealedClass() {
 }
 
 fun whenForExpectSealed(s: SealedClass): Int {
-    return when (s) { // should be error, because actual sealed class may add more implementations
+    return <!NO_ELSE_IN_WHEN!>when<!> (s) { // should be error, because actual sealed class may add more implementations
         is SealedClass.Nested.NestedDeeper -> 7
         is SealedClass.Nested -> 8
     }