Improve Attachment support

[enm10k]

TODO

• Implement a new page to manage attached files
• Implement a dialog that allows users to view file details and also rename the file there
• Request permission to notify file download completion on Android (?)

Prototype

Screen_recording_20240605_202942.webm

[ballinger]

not sure if i got the latest build (apk's have expired in githubs action tab). i am able to see the upload icon, and choices, redirect to camera or file browser work, once selected or taking a picture it returns to the app but no upload or visual feedback, as if nothing happend.