Add option to disable RDP output suppression when window is unmapped
Problem to solve
The immediate problem I have is that my RDP server will lock the (remote) screen if Remmina is hidden (e.g. on a different virtual desktop) for a long time. As long as the client window is visible, the screen stays unlocked. So I would like to make the backend behavior the same whether the window is visible or not---i.e. allow the suppression of framebuffer output [when the Remmina window is unmapped] to be disabled, with an RDP advanced option.
Further details
This can also reduce the likelihood of network traffic hiccups if the screen is updating rapidly (e.g. live video in the MS Teams client) and you are switching back and forth between Remmina and other windows. In my usage, the stability/smoothness of the connection is more important than saving bandwidth.
Proposal
I have a working implementation here. It's a fairly small change.