Add "connect" icon

[miguelsolorio]

Refs microsoft/vscode#151299

The Fluent icon system uses these two for connect/disconnect:

[ericdrobinson]

@misolori If at all possible, adding the same variants of the PlugConnected icon from the FluentUI System Icons would be very nice and make for added flexibility for VS Code UI and that of its extensions. See:

I've already proposed one solution that makes use of the "Plug Connected Add" icon from over in the source issue.

[miguelsolorio]

Thanks for the suggestions! While I wouldn't want to add specific variations without a proper justification, I'm certainly open to it.

For that specific issue, I'll wait until we have a decision on the direction before adding this icon.