Wrong encoding in the URI path of PF request

[osortega]

Dev Tunnels service seems to be doing a wrong formatting of the URI when forwarding a request to the host.
This is an example of accessing a forwarded port with a path through a web client:

Note that %40 is for some reason being unencoded and sent to the Codespace application as @, the %2F becomes %252F.

Repro steps:

1. Create a codespace from https://github.com/github/codespaces-express
2. Wait for app to start and forward port 3000
3. Access the forwarded URL on a non-existing encoded path, for example: /one%2Ftwo
4. Note error message Cannot GET /one%252Ftwo