Improve multiplayer pausing in mercenary

Kudos for adding the pause feature to PoE1. And even to the Merc league so you can properly interact with them even if a few enemies are nearby.

Sadly the pause feature in multiplayer is very frustrating in party play. If the instance leader goes to the merc the game obviously doesn't pause because it only does when all players pause. But as a party member I can't interact with the merc. I have to manually pause. This means I currently have to press ESC when the party leader talks to a merc. And then I have to manually leave the pause menu when the leader starts the fight. This is super annoying and bad to play.

2 Options I see
1) Allow everyone to interact with the merc but only the leader can start the fight.
2) Auto pause for everyone that opted in while the leader talks to the merc

And in both cases: auto unpause everyone when the fight starts. This would make merc in parties a million times more fluent.