Hide files excluded with files.exclude from Project Panel (#1626)

* Hide files excluded with `files.exclude` from Project Panel

The project panel should respect the `files.exclude` VS Code setting.
This setting is combined with the existing
`swift.excludePathsFromPackageDependencies`.

The tests required an update to `updateSettings`, as the existing global
`files.exclude` settings are combined with the ones set in the test.
When setting the settings, verify that all expected settings are present
before continuing, but don't require the settings object to be an exact
match of what we set.

* Add suite name

* Inject test dep

* Normalize paths in test

* Use vscode findFiles instead of glob

* Revert "Use vscode findFiles instead of glob"

This reverts commit 074f676.

* Watch settings for changes

* Return absolute paths from glob

* Use fast-glob instead of glob

Author: plemarquand