Update docs relating to proxies to Direct Proxies api

There's probably no reason to support legacy Proxies, rather Direct Proxies should be supported. This calls for the removal of `proxyCallTrap` and `proxyConstructTrap` and the addition of `proxyTarget`. `parameterNames` should, instead of returning an empty array, return what `parameterNames` would return for the target. I think the whole class of `DebuggeeWouldRun` errors that arise from the debuggee being a proxy could probably be removed by simply forwarding them all to the target. While this would not paint a completely accurate picture of the proxy, it's better than simply giving up.