[Feature request] Send notifications depending on terminal focus

[hardcore-sushi]

Currently, notifications are not sent if the room is in foreground on the terminal. However, users may still want to receive these notifications in the case their terminal is not visible, for example when using window workspaces or scratchpads. It looks like iamb already knows whether the terminal is focus via the Application::focused attribute. Couldn't that be used to decide whether to send a desktop notification?

[ulyssa]

Implemented in #281 by @Andrew-Collins