VSCode Plugin: preview of markdown files with space in name fails for quarto projects

[daniel-eder]

Bug description

When previewing a (q)md file that has a space in the name using the "preview" icon in the vs code editor, the opened preview url is truncated at the first space.

E.g. http://localhost:7278/Draft/13 About [17].html becomes http://localhost:7278/Draft/13

This seems to be the same issue as #240.
While the commit that closed #240 (421e4f9) introduces a more robust regex (that correctly matches the above example), it seems to fall back to previewCommandUrl_ matched with kLocalPreviewRegex in apps/vscode/src/providers/preview/preview.ts

This only happens when using a quarto project. Rendering an individual file without _quarto.yml present works.
Presumably this is the cause because for individual files the preview url is just host:port without a path.

Steps to reproduce

1. Create an empty folder.
2. Create a _quarto.yml file with minimal content for a project:

   project:
     type: default
   

3. Create a subfolder "Draft".
4. In that folder, create a qmd file with a space in it's name, e.g. 13 About [17].qmd
5. Click the preview button
6. Observe that quarto preview prints the correct url in the terminal
7. Observe that the actual preview browser opened navigates to http://localhost:<port>/Draft/13

Actual behavior

The preview browser opens http://localhost:<port>/Draft/13

Expected behavior

The preview browser opens http://localhost:<port>/Draft/13 About [17].html

Your environment

• VSCode 1.105.1
• Windows 11
• Quarto extension version 1.126.0