Edge devtools extension doesn't work on remote hosts.

Describe the bug I’m using the Edge DevTools Extension to inspect the DOM/network from within VS Code. Using the new inspector integration, as per this comment from @mliao95, doesn’t work in a remote environment (WSL or containers).

When clicking the inspector icon, rather than launching the inspector it triggers prompt to install the extension, even though it’s already installed.

This is most likely because this check fails in a remote instance as vscode.extensions.all doesn’t work as expected in remotes.

To Reproduce

1. Open a remote workspace (WSL or containers)
2. Install the nightly js-debug extension
3. Install the Edge devtools extension
4. Launch a browser with client-side debugging (either Open Link or a launch task of pwa-edge)
5. Click the inspector icon
6. Expected Edge extension to show the inspector. Actual Prompted to install the extension

VS Code Version:

Version: 1.57.0-insider (system setup)
Commit: bf84ee619e0b67443d0307c04348fa575bc3c363
Date: 2021-06-07T12:46:22.208Z
Electron: 12.0.9
Chrome: 89.0.4389.128
Node.js: 14.16.0
V8: 8.9.255.25-electron.0
OS: Windows_NT x64 10.0.19043

Additional context

I’ve cloned the js-debug extension, removed the check for the Edge extension and side-loaded it into a container. That does result in the expected behaviour of click inspector -> get Edge inspector but the Edge inspector doesn’t properly connect. The DOM inspector doesn’t show any DOM nodes and the Network tab doesn’t have any traffic in it. My assumption is that the debugger isn’t forwarding requests through properly in a remote environment, but how that all works is beyond what I’ve been able to discover.

Here’s a video of it in action, using my modified version of the js-debug extension. An issue has also been opened on the vscode-edge-devtools issue register, to keep that team in the loop too.

https://user-images.githubusercontent.com/434140/121441188-aabdaa00-c9cc-11eb-9322-cd43fe8165ad.mp4

[connor4312]

I think @bgoddar still needs to adopt+publish the changes on the Edge devtools extension side of things.

[connor4312]

1. Check to see if the edge debug extension is running in the workspace ([e.g.]https://github.com/microsoft/vscode-js-debug/blob/baacf1949db03a34ee8ad2160cc77f21c371a77a/src/extension.ts#L37))
2. If not, pass forwardToUi: true as a second argument to extension.js-debug.requestCDPProxy
3. I’ll return back a forwarded port