fix: Stop Discovery when client gets into Connected state

syntax

fix: MirrorNetworking#2739: NetworkServer.Update now operates on a co…

…py of connections so transports can call OnTransportDisconnected from within send. avoids 'collection can't be modified while iterating' exception

fix: fixing NetworkDiagnostics receive for batching (MirrorNetworking…

…#2700)

NetworkWriterTest: use CreateNetworked

feat: Added Stop buttons to Discovery HUD

Copied from NetworkManagerHUD

perf: NetworkBehaviour ComponentIndex O(N) => O(1) via caching

fix test after NetworkWriter Length removal

fix: Reset Network Time whenever server starts (MirrorNetworking#2713)

NetworkServer broadcasting: GetEntitySerialization helper function