Align externalId

externalId for any field in stubElementTypeHolder has to be prefix (`kotlin`) + dot (`.`) + field name

#KT-53781

compiler/tests/org/jetbrains/kotlin/psi/KtStubElementTypesExternalIdTest.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.psi
+
+import com.intellij.psi.stubs.ObjectStubSerializer
+import junit.framework.TestCase
+import org.jetbrains.kotlin.psi.stubs.elements.KtStubElementTypes
+
+class KtStubElementTypesExternalIdTest : TestCase() {
+    fun testExternalIds() {
+        val clazz = KtStubElementTypes::class.java
+        for (declaredField in clazz.declaredFields) {
+            val stubSerializer = declaredField.get(null) as? ObjectStubSerializer<*, *> ?: continue
+            val name = declaredField.name
+            val externalId = stubSerializer.externalId
+            assertEquals("kotlin.$name", externalId)
+        }
+    }
+}