siw: respect 'files.exclude' preference

[vince-fugnitto]

What it does

Fixes: #7273

The following pull-request updates the search-in-workspace search to respect the files.exclude preference (which describes glob patterns for exclusion). Currently, the files.exclude preference is not respected and the search yields incorrect results such as **/*.git.

How to test

• searching through the search-in-workspace should work correctly.
• searching should not yield results which are described by the files.exclude globs.
• overriding the default globs (using the boolean value) should work.
• the newly added test case to test exclusion should work correctly.

Examples:

Exclude: **/*.git = true	Exclude: **/*.git = false

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

[paul-marechal]

LGTM, was able to ignore patterns!

There's a discrepancy with the way VS Code handles patterns (.json on VS Code works like *.json on Theia) but it is fine to keep this for later improvements.

[vince-fugnitto]

LGTM, was able to ignore patterns!

There's a discrepancy with the way VS Code handles patterns (.json on VS Code works like *.json on Theia) but it is fine to keep this for later improvements.

Thank you for the review, I'll leave the pull-request open for a couple of days so others can get a chance to verify as well 👍

[Anasshahidd21]

The changes work well for me.

Tested on Gitpod.