Allow Customize.Mode.APPEND for permittedLinkParameterNames Handlers

It is now possible to add entries to the permittedLinkParameterNames of handlers via customizer.

(CMS-21890)

Ignore View Name on File Navigation Attempts

When a request with a suspicious view name is provided that tries to traverse the filesystem, the view will now be ignored instead of forwarding to an error page. This is the same behavior like for other invalid view names. For such suspicious requests, an info will be logged.

(CMS-19122)