Fixes:
* Change download URL to `https://www.linphone.org/technical-corner/linphone`
* Crash on contacts list when deleting a friend and trying to load logs.
* Message status behaviour : Resuming status when changing logs, cursor shapes updates, bind the `resend message` action to error icon
* Synchronize settings and main presence.
* QML Crashs on fullscreen
Features :
* Add utilities in fullscreen view (media quality, security, mutable speaker)
* Show fullscreen on the current call screen
* Show Display name of participant in conference
* Participants in conference are mutable
- Add External Image Provider to avoid having error message when we try to show a file that is not an image (used to show an attachment where it can be a regular file).
- When creating an image, try to read the headers of a file when the extension is not consistent with contents.
- Build if not exists, a thumbnail image if the file has been displayed when filling a message
- When trying to open the file, test if it was downloaded by reading the flag
- Add a status for File Transfert In Progress
- Use non-deprecated function to get file path from ChatMessage
- Use FileSize in addtion of content Size to get the full size of a message
- Show a progressbar when downloading a file
- Show the image in notification when downloaded or the file name if it is not an image
