Add search form for /nojs endpoint

Adds an html form to search books by the q= parameter

include/html_dumper.h

@@ -42,7 +42,7 @@ class HTMLDumper : public LibraryDumper
    *
    * @return HTML content
    */
-  std::string dumpPlainHTML() const;
+  std::string dumpPlainHTML(kiwix::Filter filter) const;
 };
 
 }