Minor The WOPI discovery contains other apps than Word, Excel & PowerPoint.
For instance
<app name="OneNote> <app name="Visio"> <app name="WordPdf">
Currently, we don't want to dsplay the WOPI link for a PDF file because viewing PDF documents in Office Online is in the process of being deprecated, see https://wopi.readthedocs.io/en/latest/faq/pdf_support.html, and it just doesn't work!
We need a way to whitelist the apps that we want/know how to deal with, using a list configuration property.
