Once #5354 goes in the concept of an autoaccepted downloaded file becomes a little less clear. Since the file downloads will now be part of history we want to keep track of them ourselves.

Since we want to keep track we should move the default download's directory out of a folder that will be routinely pruned by users. As discussed in #5348 we will now

• Default download to Settings::getAppDataDirPath() / transfers /
  • Apparently we already do friend ID hashing for avatars
• User should be able to directly open storage for each conversation through some UI element in order to clean up file storage
• While we're at it we should probably move screenshots to the same directory