Repopulate data attr upon samples and library changes

[avrohomgottlieb]

Issue Number

Closes #1589.

Purpose/Implementation Notes

This PR updates the Dataset::get_or_find_ccdl_dataset method to repopulate it when datasets are retrieved. This is especially necessary when samples and/or libraries have been added or removed from a project that the dataset references.

Types of changes

What types of changes does your code introduce?

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Functional tests

• Additional assertions added to test_dataset::test_get_or_find_ccdl_dataset

Checklist

• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works

Screenshots

Please attach any screenshots that illustrate these changes.