Blurry app provider icons

[Aitorbp]

Is your feature request related to a problem? Please describe.

About this pull request, we receive the URLs of the icons from the app providers, they do not have a good resolution and they look a little blurry in the operations menu. I think the endpoint where we receive this information is in index.php/app/list.

Describe the solution you'd like

Now the icon has a .ico extension, it would be good to change these icons for others that are vectorized or at least with better resolution to avoid blurry behaviour in the image.

Additional context

We have detected this because previously on Android we were hardcoding the icon and we did not use the ones that came to us from the server. I am attaching a screenshot of how the icons look on android:

These are the urls of the icons we receive from the server in this example:
https://collabora.ocis-wopi.latest.owncloud.works/favicon.ico
https://onlyoffice.ocis-wopi.latest.owncloud.works/web-apps/apps/documenteditor/main/resources/img/favicon.ico

I have noticed that on other servers there is a specific image with a better resolution. Icon URL:
https://www.collaboraoffice.com/wp-content/uploads/2019/01/CP-icon.png