- Lock-free UDP proxy forwarding by puttng front and back end on the
same thread.
- Cleans up some Swift language awkwardness in the proxies.
## Type of Change
- [ ] Bug fix
- [x] New feature (optimization)
- [ ] Breaking change
- [ ] Documentation update
## Motivation and Context
Proxies worked but could be made lock-free.
## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [ ] Added/updated docs