Assert that the separation of two annotations on function type during rendering it, is any whitespace-like symbol, not only whitespace itself

E.g. in quick doc mode (HTML), it may be line break

^KT-38747 Fixed

idea/testData/editor/quickDoc/renderAnnotatedExtensionFunctionType.kt

@@ -0,0 +1,9 @@
+fun myFun<caret>(param: @MyAnnotation (String.() -> Unit)) {} // quick documentation myFun
+
+@Target(AnnotationTarget.TYPE)
+annotation class MyAnnotation
+
+//INFO: <div class='definition'><pre><font color="808080"><i>renderAnnotatedExtensionFunctionType.kt</i></font><br>public fun <b>myFun</b>(
+//INFO:     param: @<a href="psi_element://MyAnnotation">MyAnnotation</a>()
+//INFO: (String.() &rarr; Unit)
+//INFO: ): Unit</pre></div></pre></div><table class='sections'><p></table>