Fix Image Loading When Offline

[alexknop]

Problem:

Although Videos were loading immediately when offline, Images were not

Solution:
Found that checking for whether file is offline was passing, but the ! in the code was making it false, forcing a sync which would timeout (taking extra time) and preventing immediate access to images

Fixes #14470

[alexknop]

It still takes a long time to load images when on cellular.

My server address is 192.168.1.2 and as I test this on a guest Wi-fi network with 192.168.1.0/24 as well, it seems Nextcloud is quicker to detect my server unreachable on here versus on Cellular. However, load times are much better when on the guest Wi-Fi and loading images due to this code change.

Videos always load immediately regardless of WiFi or Cellular

[alexknop]

I dug more into it and found the timeouts for ReadFileRemoteOperation were extensive by default but you can customize the timeouts. By lowering them, the connection error happens sooner and the app responds quicker.

Images are now loading fine when on cellular and I cannot reach my server.
Please consider these changes and lets discuss.

[alexknop]

Found another area to reduce timeouts and speed up the app, that is the timeouts for OCVersionCheck.

Changed them to 1000 and app is responding better when offline.

[alperozturk96]

Thank you for the PR.

RefreshFolderOperation/ReadFileRemoteOperation may need more time. If we lower the default session time out value, the user may not get the latest result.

Default = SessionTimeOut(60000, 15000)
PR = SessionTimeOut(1000, 1000)

@tobiasKaminsky Most likely it will fail, and 1 second is very low. What do you think?