Allow Zed to run under multiple user accounts simultaneously

[samsonjs]

Closes #4607

This is an attempt to enable Zed to run under multiple user accounts on the same Mac, because it's a blocker to me really giving Zed a fair shot at being my primary editor.

According to some helpful info from @ForLoveOfCats in #4607 the main reason why this doesn't work is because Zed is using a Unix socket or maybe a TCP socket with a hard-coded path and/or port. To me it looks like it's a TCP socket so I tried changing that code in here, but I'm stuck at trying to test it out because running target/debug/zed or target/release/zed seems to behave differently than running an actual app bundle. I had no luck copying the binary over to /Applications/Zed.app/Contents/MacOS/zed because it can't find WebRTC.framework which resides at a different relative path in the app bundle.

If this seems like a desirable change to the core team then I'm looking for some guidance on how to build an app bundle or otherwise test out this change, or a nudge in the correct direction if I'm way off base with my current approach.

Release Notes:

• Added multiuser support for up to 100 users on the same machine.

[helloanoop]

Closing this since this functionality was taken care of in #3178