vscode ext ID mapping to cursor ext ID mapping for brev open cursor

[cloin]

This creates a mapping between the expected vscode remote-ssh extension to the proper remote-ssh extension in cursor. Fixes this:

% brev open gpu_instance cursor                 
finding your instance...
⣟ Instance is ready. Opening Cursor 🤙 
Couldn't install the necessary Cursor extension automatically.
Error: 0 errors occurred:
	
	Please install Cursor and the following Cursor extension: ms-vscode-remote.remote-ssh.

Hit enter when finished: █

Previously:

• The code checks if ms-vscode-remote.remote-ssh is installed in Cursor → Not found (because Cursor uses a different ID)
• Tries to install ms-vscode-remote.remote-ssh → Succeeds (the extension gets installed)
• Checks again for ms-vscode-remote.remote-ssh → Still not found (because it's listed as anysphere.remote-ssh)
• Show error message with "0 errors occurred" (all CLI commands succeeded, but extension appeared missing)

https://linear.app/nvidia/issue/BREV-1721/brev-open-command-not-working

[drewmalin]

Nice 👍