Add Unity Netcode for Entities SDK

[GabrielBoninUnity]

Hi guys. Gab again
We would like to add Unity Netcode for Entities to your SDK list. Here is a quick list of games on Steam that use Netcode for Entities:
https://steamdb.info/app/1079260/
https://steamdb.info/app/1011670/
https://steamdb.info/app/2776270/
https://steamdb.info/app/2871520/

This PR adds a new filter for the Unity Netcode for Entities SDK to SteamDB, to track which released Steam games are using this package for high-performance multiplayer functionality.

Background
Unity Netcode for Entities is a server-authoritative networking solution built specifically for Unity's Entity Component System (ECS). It enables developers to create high-performance multiplayer games using a data-oriented approach, making it ideal for games that require large-scale simulations, massive player counts, or complex networked gameplay with minimal overhead.

Why Add This Filter?
High-Performance Solution: Netcode for Entities is designed for games that need to scale to hundreds or thousands of networked entities, making it the go-to solution for performance-critical multiplayer games built with Unity DOTS (Data-Oriented Technology Stack).

Growing Adoption: As more developers adopt Unity's ECS architecture for performance reasons, Netcode for Entities is becoming increasingly important in the Unity multiplayer ecosystem.

Improved Insights: Having this detection will provide valuable insights into which games are leveraging Unity's cutting-edge data-oriented multiplayer technology.

Technical Details
This PR detects the presence of Unity.NetCode.dll, which is the core runtime library for Netcode for Entities.

[xPaw]

I've checked, not enough games use this (less than 50) to warrant adding yet another Unity plugin, as I believe we've previously discussed - we don't want to track every Unity plugin.

P.S. https://github.com/sponsors/xPaw