[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-api/testData/symbols/symbolByReference/javaMethodWithExternalNotNullAnnotation.kt

@@ -0,0 +1,14 @@
+// FILE: main.kt
+fun some() {
+  JavaClass().f<caret>oo();
+}
+// FILE: JavaClass.java
+public class JavaClass {
+  public String foo() {};
+}
+// FILE: annotations.xml
+<root>
+  <item name='JavaClass java.lang.String foo()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+</root>