[BUG]: `Dev Proxy Toolkit: Stop` command not shutting down process

[garrytrinder]

We provide a command for shutting down the active Dev Proxy process, whilst it stops the active Dev Proxy process, it does not disable the HTTP and HTTPs proxies on the network adapter. The proxies must manually be disabled to let traffic through after stopping Dev Proxy.

[garrytrinder]

The issue was caused by the code that disposes of the terminal window after the request that is sent to the local API to stop Dev Proxy. We need to wait to ensure that the process has stopped before disposing of the terminal.