Platform header annotator: implementation + simple multi-platform highlighting tests #KT-14905 Fixed

idea/testData/multiModuleHighlighting/platform1/header/header.kt

@@ -0,0 +1,3 @@
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] No implementation is found for header declaration 'My'">My</error> {
+
+}

idea/testData/multiModuleHighlighting/platform1/jvm/jvm.kt

@@ -0,0 +1,15 @@
+<error descr="[IMPLEMENTATION_WITHOUT_HEADER] Modifier 'impl' is only applicable to members that are initially declared in platform-independent code">impl</error> class Your {
+
+}
+
+header class <error descr="[HEADER_WITHOUT_IMPLEMENTATION] No implementation is found for header declaration 'His'">His</error> {
+
+}
+
+header class Their {
+
+}
+
+impl class Their {
+
+}