Fix issue when there is no root module

[johlju]

Pull Request

Pull Request (PR) description

Fixed

• Fix issue when there is no root module.
• Fix to use correct path when determine class-based resources.

Task list

• [x] The PR represents a single logical change. i.e. Cosmetic updates should go in different PRs.
• [x] Added an entry under the Unreleased section of in the CHANGELOG.md as per format.
• [x] Local clean build passes without issue or fail tests (build.ps1 -ResolveDependency).
• [ ] Resource documentation added/updated in README.md.
• [ ] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [ ] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [ ] Examples appropriately added/updated.
• [ ] Unit tests added/updated. See DSC Resource Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• [x] New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

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This change is