Add Active Players and Bots displays to Status Bar

[thomeval]

This PR adds two displays to the top Status Bar to display the currently active players, as well as the number of active bot profiles. These can be toggled in the Settings menu using the "Show Active Players" and "Show Active Bots" options.

Notes:

• Show Active Players is enabled by default. Show Active Bots is not.
• Only the number of active bots is shown, since their names are probably not useful.
• The active bots display is hidden automatically if no bot profiles are active (similar to the Battery status display).
• When 1 to 3 players are connected, their instrument icons and profile names are shown.
• When 4 or more players are connected, only their instrument icons are shown.
• However, when no players are connected (including bots), the active players list will instead show a "No profiles active" message.
• The current implementation is not very efficient, as it Destroys and Instantiates prefabs on every update (once a second). Advice on how to address this (or leave it as-is) is welcome.

[thomeval]

Thanks for the feedback. I'll make the changes discussed above and get back to you.

[thomeval]

I've updated this branch with the requested changes, and did a quick test to see if everything is still working as it should. I've needed to update ProfileListMenu as well in order to fix a bug where player instrument icons weren't updating when players change their Game Mode.