crash when reading a message on Outlook

[tomholub]

1. log in with outlook
2. set up (in my case with pass phrase saved to device)
3. open any email in inbox
4. crash

This is likely caused by my async/await refactor, didn't check IMAP that time

[Kharchevskyi]

@tomholub @sosnovsky
It looks like MessageViewController is removed in scope of this pr #1017 which was used for opening messages.

"Other email provider option" does not support message threads functionality.

[sosnovsky]

Yes, MessageViewController was removed, but ThreadDetailsViewController should support single messages too - Thread with 1 message is created for this case https://github.com/FlowCrypt/flowcrypt-ios/blob/master/FlowCrypt/Controllers/MessageList%20Extension/MsgListViewController.swift#L40

[Kharchevskyi]

Looks like it doesn't support operations with messages (archive/delete/mark as unread) and it can't resolve dependency for this controller

Fatal error: Email Provider should support this functionality. 
Can't resolve dependency 
for Optional<MessagesThreadOperationsProvider>

[sosnovsky]

Yes, seems like we've missed this functionality there, as it was tested mostly with Google accounts, while IMAP accounts functionality wasn't high priority. We still has some issues for it - like #989 and #484

[Kharchevskyi]

Should we revert those changes?
Or add support for message operations? Which can take some time

[sosnovsky]

Reverting changes will need re-duplicating of all code which was added to ThreadDetailsViewController since then, which will take some time too.

We already have messageOperationsProvider in ThreadDetailsViewController, it can be used for performing operations when there is a single message instead of thread. Just need to identify which message type we have - message or thread and then use messageOperationsProvider or threadOperationsProvider accordingly.

[tomholub]

We should definitely not revert the changes - MessageViewController was removed purposefully, since ThreadDetailsViewController can be used to render a thread containing 1 message as well.

We don't have to fix message operations in this issue. I'll file another issue for that. Just viewing the message.