Udp socket startup should not crash when the NanoSockets native library is unavailable on a desktop platform.

When automatic UDP socket selection cannot load the native NanoSockets library, startup should fall back to the managed C# UDP implementation instead of throwing a native DLL load error.

Expected behavior:
- Missing native NanoSockets library should not throw during UDP socket factory startup.
- Automatic socket selection should fall back to the managed UDP path.
- Existing unsupported-platform checks should remain unchanged.

--- Original GitHub issue (auto-fetched) ---
Title: No Error when building 32 bit windows with Nanosockets

Body:
**Describe the bug**
Nanosockets only as a 64 bit dll. if a 32 bit build is made then it will give an error: `DllNotFoundException: nanosockets`

We should give a build error if Nanosockets is used in 32 bit build
