log screen prevents scrolling up

[Roasbeef]

On the desktop application it isn't possible atm to scroll up in the log view. The current issue is that as logs get appended to the end of the view, the scroll-back gets automatically dragged to the newest entry preventing the user from viewing any of the earlier entries.

[skv-headless]

@valentinewallace may I take this one? I'm planning to prevent auto scrolling if logs scrolled and show "New messages" button which scrolls to bottom when clicked