Add Custom Server Icons for Bedrock Edition Servers

In Java Edition, server owners can add custom server icons, which helps players quickly recognize servers and improves server list usability and branding. Bedrock Edition currently has no official support for server icons, even for local or self-hosted community servers. Many Bedrock players run SMPs, community servers, and crossplay servers, and this visual feature would greatly improve the multiplayer experience without affecting gameplay or performance. Adding server icon support to Bedrock Edition would also improve feature parity between Java and Bedrock and reduce confusion when players join multiple servers.