Updates UI address in active browser tab when using the connect command (closes #2558). Doesn't change browser tabs. Updating the active tab seems good already. Initial connect command not supported. Instead, command manager should be able to buffer some commands (only connect right now) and only invoke the command chain after initialization.

Relying on the UI m_SelectedCommand for executing commands was a bad idea to start with, if you typed /wh then backspace + space to get to /w  whisper would still be executed instead of w. In other words executing commands that are a superstring of other commands was tough to use. I also reverted the instant whisper as per #2525 and fixed a small UI oddity. Sorry this feature turned out such a mess, missed a little too much

Settings Max fps higher than the UI limit looks odd. Should we do anything about that? !screenshot_2020-04-15_12-42-11

An instance where this is very visible: !screenshot_2020-04-15_12-40-22

Adds a primitive notification system. Close #2549

Even if we are out of bounds of the scrollbar, render the handle at the extremities.