Include ignored files in vscode.workspace.findFiles

[msujew]

What it does

Closes #6460

Extends the options used for finding files via the VS Code API. The current API was very limited and could not correctly identify whether to exclude git ignored files.

This change adjusts the options to always include git ignored files when calling vscode.workspace.findFiles.

How to test

1. Download and install this test plugin (source here)
2. Open the example folder.
3. Run the Test: Find Files command.
4. It should find 3 files (only finds 2 on master).

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[tsmaeder]

So this PR aligns the behaviour with the doc at https://code.visualstudio.com/api/references/vscode-api#FileSystem, right? In particular when exclude is null.

[msujew]

So this PR aligns the behaviour with the doc at https://code.visualstudio.com/api/references/vscode-api#FileSystem, right? In particular when exclude is null.

Yes, the PR in general is just there to align the behavior of findFiles to VS Code.

[tsmaeder]

@msujew something seems amiss here: Here's what I do:

1. I add the file "a.txt" to the sample folder (it seems to be required, but missing)
2. I open the sample folder
3. I do "Test Find Files".
4. I get 3 results, whether with or without this PR. What gives?

[msujew]

@tsmaeder I'm actually confused as well - I didn't really test the behavior previously on Theia, I just assumed the report over at #6460 (comment) to be accurate. However, I cannot reproduce this issue either on master right now. Asking for better repro steps on the issue.