[Azoth Murm] PendingUpload stub.
[Azoth Murm] Added TransferManager.
[Azoth Murm] Request `docs` permission.
[Azoth Murm] Request upload server.
[Azoth Murm] Initiate document upload.
[Azoth Murm] VkEntry::FindEntryById().
[Azoth Murm] Support attachments for out messages.
[Azoth Murm] VkAccount::GetLogger().
[Azoth Murm] Guarded entry in PendingUpload.
[Azoth Murm] Invoke docs.save on documents upload.