Better handling of images

Right now, adding images (or any files) to chats requires you to have the image uploaded to nextcloud. You have to select the image where ever it is located in your files and then when viewing it just opens the folder where it is uploaded. Also in the app to view it effectively you have to tap it which opens a web browser which makes you log in.

I think that attached files should be handled better. When opening a image/file in a chat, the native nextcloud viewer for that filetype should open.

Just opening the folder is really annoying and makes me want drop the app from my server.