KT-46063 Quick fix: remaining when branches for 'expect' sealed

'List<WhenMissingCase>.hasUnknown' property was changed in 4222bb9a.
As a result quickfix's AddWhenRemainingBranchesFix.Companion.isAvailable
started responding 'no'.
This commit restores original property and provides a separate one for
compiler needs.

^KT-46063 Fixed

idea/testData/multiModuleQuickFix/createActual/expectSealedInCommonWhen/header/header.kt

@@ -0,0 +1,14 @@
+// "Add remaining branches" "true"
+// SHOULD_BE_AVAILABLE_AFTER_EXECUTION
+// ERROR: Expected class 'CommonSealedClass' has no actual declaration in module testModule_Common
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+
+expect sealed class CommonSealedClass()
+class SInheritor1 : CommonSealedClass()
+class SInheritor2 : CommonSealedClass()
+
+fun hello(c: CommonSealedClass): Int = <caret>when(c) {
+
+}

idea/testData/multiModuleQuickFix/createActual/expectSealedInCommonWhen/header/header.kt.after

@@ -0,0 +1,16 @@
+// "Add remaining branches" "true"
+// SHOULD_BE_AVAILABLE_AFTER_EXECUTION
+// ERROR: Expected class 'CommonSealedClass' has no actual declaration in module testModule_Common
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+
+expect sealed class CommonSealedClass()
+class SInheritor1 : CommonSealedClass()
+class SInheritor2 : CommonSealedClass()
+
+fun hello(c: CommonSealedClass): Int = <selection><caret></selection>when(c) {
+    is SInheritor1 -> TODO()
+    is SInheritor2 -> TODO()
+    else -> TODO()
+}

idea/testData/multiModuleQuickFix/createActual/sealedInCommonWhen/header/header.kt

@@ -0,0 +1,12 @@
+// "Add remaining branches" "true"
+// SHOULD_BE_AVAILABLE_AFTER_EXECUTION
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+
+sealed class CommonSealedClass()
+class SInheritor1 : CommonSealedClass()
+class SInheritor2 : CommonSealedClass()
+
+fun hello(c: CommonSealedClass): Int = <caret>when(c) {
+
+}

idea/testData/multiModuleQuickFix/createActual/sealedInCommonWhen/header/header.kt.after

@@ -0,0 +1,13 @@
+// "Add remaining branches" "true"
+// SHOULD_BE_AVAILABLE_AFTER_EXECUTION
+// ERROR: Unresolved reference: TODO
+// ERROR: Unresolved reference: TODO
+
+sealed class CommonSealedClass()
+class SInheritor1 : CommonSealedClass()
+class SInheritor2 : CommonSealedClass()
+
+fun hello(c: CommonSealedClass): Int = <selection><caret></selection>when(c) {
+    is SInheritor1 -> TODO()
+    is SInheritor2 -> TODO()
+}