Issue Type: Bug

After updating to 1.43.0, when VSCode relaunched, it brought up around 80 editor windows from old projects I hadn't opened in quite some time. (spooky workspace necromancy)

Perhaps obviously this made my computer behave quite poorly. I tried adding "window.restoreWindows": "none" to my <config>/User/settings.json with another text editor, but it didn't seem to be respected (might be my fault somehow). Note that it had been on "folders" previously, in case that helps.

I also tried to muck about with <config>/storage.json file. VSCode seemed to ignore my changes to it (probably not a bug -- I was desparate and dunno how this file works), but I do have a backup of a storage.json from right after this happened. It shows all the windows it will try to open when launching, and maybe other stuff. If there's no PII concern beyond the file paths I can upload it. I guess the system info probably has more PII anyway. I dunno how much this helps but: https://gist.github.com/thomcc/c4f9a745d940d8e0bfd5d28946c73bdc

I think the main common feature of the workspaces it resurrected seemed to be that they had open files with unsaved changes -- but these are also the ones which can't be closed without additional UI confirmation, and I did try a couple things to close all windows in bulk (none seemed to work, but maybe I just didn't notice?)

Relaunching without extensions also didn't help, but that doesn't mean this wasn't caused by an extension in the first place or somethign. I have more than is probably reasonable installed. That said, it happening immediately after updating to 1.43.0 makes me think it's vscode and not an extension.

Anyway, ultimately I just bit the bullet and closed them manually -- VSCode would be usable for about 20 seconds after starting, during which time I could close a few before too many were restored and everything got too slow. So i just did this, quit, and repeated many times until there were no more left (this actually took a couple goes -- even when I'd get down to none left, save, and reopen, it would find some new ones to bring back... Guessing these just didn't make the cut for being restored the previous time, or something)

P.S. it would be nice if there were a command line argument to launch without reopening anything.

P.P.S. In case it isn't clear: I've been using editor, workspace, and window somewhat interchangably here, just so you don't think I'm being precise about which I use when.

VS Code version: Code 1.43.0 (78a4c91, 2020-03-09T19:34:44.548Z)
OS version: Darwin x64 18.7.0