[FIR] add tests on external annotations

Tests are excluded in COMPILED_JAVA mode because in this
mode external annotations are not present at all

^KT-62310

analysis/analysis-test-framework/tests/org/jetbrains/kotlin/analysis/test/framework/project/structure/TestModuleStructureFactory.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2023 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.
  */
 
@@ -183,7 +183,7 @@ object TestModuleStructureFactory {
     fun createSourcePsiFiles(
         testModule: TestModule,
         testServices: TestServices,
-        project: Project
+        project: Project,
     ): List<PsiFile> {
         return testModule.files.map { testFile ->
             when {
@@ -192,7 +192,7 @@ object TestModuleStructureFactory {
                     KtTestUtil.createFile(testFile.name, fileText, project)
                 }
 
-                testFile.isJavaFile -> {
+                testFile.isJavaFile || testFile.isExternalAnnotation -> {
                     val filePath = testServices.sourceFileProvider.getRealFileForSourceFile(testFile)
                     val virtualFile =
                         testServices.environmentManager.getApplicationEnvironment().localFileSystem.findFileByIoFile(filePath)
@@ -205,7 +205,5 @@ object TestModuleStructureFactory {
             }
         }
     }
-
-
 }