[TF2][Feature Request] Add a way to know a team_control_point entity's capture progress

[lezoisoi]

It would be handy for the control point entity to have outputs co-relating to its capture progress.

My proposed implementation of this would be two outputs for the team_control_point entity along the lines of On(Team)CapProgress, which would fire whenever the capture progress changes for the specific output's team, with the parameter provided being the capture progress between 0 and 100.