feat: Add public UcrEvents bus and CustomTeamId for external plugin integration

[AdzAhm]

Hi everyone! 👋
I’m a uni CE stuendt while improving my GitHub profile I stumbled back onto this project from when I used to play/develop and modrate for SCP:SL servers.
I saw a recent feature request (not really recent a year ago lol) for custom winning conditions and noticed the plugin owner mentioned that updating the old EndConditionsExtension was the best way to handle it. I decided to take on the challenge and have updated the extension to make this possible!
Note: I have opened a PR on the extension's repo as well.
Because I am busy with university and deleted the game , I am not able to test these changes in a server. I would hugely appreciate it if the community or maintainers could test the updated plugin and extension to ensure everything is working correctly.

Here is a breakdown of the technical changes made in this PR:

Adds a new public API to allow external plugins (like EndConditionsExtension) to cleanly hook into custom role lifecycles without relying on internal Harmony patches.

Changes:

• Added UcrEvents public static event bus with CustomRoleAssigned, CustomRoleRemoved, and CustomRoleEscaped events.
• Added optional CustomTeamId string property to ICustomRole, CustomRole, and EventCustomRole to allow multiple custom roles to share a "faction" identity (e.g., "SerpentHand").
• Updated SummonedCustomRole and PlayerEventHandler to fire these events during spawning, destruction, and natural/custom escaping.

Note: These changes are entirely additive and do not alter existing plugin behavior.

2nd note:It's been a long time since I coded SCP:SL plugins, so please excuse any messy code or silly errors! 😅

[AdzAhm]

!!

[FoxWorn3365]

I'll take a look this evening
Btw the custom team identifier should also be added to the ICustomRole interface

[AdzAhm]

check UncomplicatedCustomServer/EndConditionsExtension#1
this is why the change was made in the first place