add skipLock option to window creation

[GameParrot]

Adds skipLock to mcpelauncher_show_window and mcpelauncher_close_window

[ChristopherHX]

I know the problem you are currently facing, but I'm still not happy with your approach of replacing a deadlock by data inconsistency errors that are hard to debug.

Inconsistent data structures, by modifying collections that are used to iterate.

I could rewrite the api so mcpelauncher_show_window and mcpelauncher_close_window no longer need to hold the lock that is used by the imgui render loop.

Your mod can use std::thread to call them in a new thread with their parameters on the stack as well.

[ChristopherHX]

a recusive_mutex could fix the deadlock as well, but still has data inconsistency for closing / updating windows (create new is ok with a recusive mutex as I used a for loop with i).