Multiplayer PlayMode add editor methods to modify settings exposed in the UI

[CodeSmile-0000011110110111]

Is your feature request related to a problem? Please describe.
In MPPM 1.0.0 there is no way to add/remove the Player tags via an editor script, neither to the Project Settings list nor is it possible to assign virtual players specific tags and multiplayer roles. 

This would come in very handy for quick configuration changes, and initial project setup for (template) assets.

There should be a public editor API to get/set the player tags list, and methods to assign tags and multiplayer roles to virtual players. Also a way to change the main editor's multiplayer role setting via script.