Additional improvements for PT-140709005

For missing properties in toplevel nodes, place the error marker at the
end of the document.

vscode-extensions/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/util/DocumentRegion.java

@@ -283,4 +283,11 @@ public class DocumentRegion implements CharSequence {
 		return false;
 	}
 
+	/**
+	 * Create a document region of lenght 0 at the every end of the document.
+	 */
+	public static DocumentRegion endOf(IDocument doc) {
+		return new DocumentRegion(doc, doc.getLength(), doc.getLength());
+	}
+
 }