Expose team changes and settings to APIs

[Liparakis]

What Changed

This PR adds addon-facing client/server API hooks around shared multiplayer state and removes a couple of rough edges from the initial implementation.

Main changes since 4d6c01f:

• Added IClientManager.Id so addons can access the local player's assigned network ID on the client.
• Added IClientManager.ServerSettings so addons can read the current shared gameplay settings on the client.
• Exposed change notifications on IServerSettings through OnChanged, which is now the single client-side settings change hook.
• Added OnTeamChanged to both IClientPlayer and IServerPlayer.
• Updated ClientPlayerData and ServerPlayerData so team property changes raise OnTeamChanged.
• Updated the client connect path to create/store the local ClientPlayerData using SelfId.
• Updated the local team-change path so the local player's ClientPlayerData.Team is also updated, making IClientPlayer.OnTeamChanged work for self as well as remote players.

Why

The goal of the PR is to support four addon use cases cleanly:

• read server settings on the client
• react when server settings change
• react when a player changes team
• read the local player's own ID on the client

[Extremelyd1]

Thanks for the PR, changes to the API are always welcome.
I've left a few comments about simple things, but I would like you to revert exposing the local player's network ID as discussed, since it is unnecessary.

[Liparakis]

I reverted the UserID exposure and applied the fixes you requested. Also i implemented an Interface under the API which allows addon to read ModSettings and Subscribe to the ChangedEvent.

[BobbyTheCatfish]

Just a thought, maybe there should be an event on ClientManager for when your own team changes? And maybe an event for when any player's team changes so that you don't have to hook each player individually? Something like OwnTeamChangeEvent and PlayerTeamChangeEvent, (but with better names ofc)?

[Extremelyd1]

@Liparakis do you want to implement those additions from @BobbyTheCatfish still in this PR before I review?

[Liparakis]

[Extremelyd1]

A couple of comments for some unintended behaviour.

Also, when reading Bobby's comment I thought that it might be better if we either move the TeamChangedEvent from IServerPlayer (on the server-side) to IServerManager and have it be an Action<IServerPlayer, Team> so it is easier to deal with.
Then, you can also hook team changes server-side in general, without having to hook every individual player. Otherwise, if an addon needs to deal with team changes globally they'd need to hook PlayerConnectEvent, then hook the TeamChangedEvent. And probably for cleanup, you'd need to hook PlayerDisconnectEvent also to remove the hook on TeamChangedEvent for the player. Otherwise, GC won't kick in because of references.

[Extremelyd1]

I've done some additional cleanup.
Most impactful is that I've moved the team change events on the client-side to a separate interface IPlayerManager that more closely resembles the underlying implementation.