Allow custom ServerSelectorTypes when connecting players to a task or a group

[0utplay]

Describe the new feature

Rework the ServerSelectorType in a way that an api user can create and add own ServerSelectorTypes and use them when connecting a player.

Why do you need this feature?

At some places you might want to sort using the name of the service or another property instead of the player count.

Alternatives

Doing all the work ourselves, filtering, sorting and finally connecting the player

Other

No response

Issue uniqueness

• [X] Yes, this issue is unique. There are no similar issues.