Open File: unable to open a file with spaces in name if absolute path is provided

[bpasero]

Steps to Reproduce:

1. open quick open (Cmd+P)
2. paste the absolute path of an existing file that contains spaces (for me: C:\Program Files\Microsoft VS Code Insiders\resources\app\out\vs\code\electron-main\main.js)

=> no results shown to open

[humphd]

I was teaching my students about workflows for fixing bugs in VSCode, and used this bug as an example. I wrote them a guide at https://github.com/humphd/vscode/tree/good-first-experience-issue-42726#walkthrough-fixing-a-bug-in-visual-studio-code.

I was going to do a PR, but it looks like one of them beat me to it, so I'll let @aushakou continue.

[bpasero]

Good findings 👍