Get- and Copy-DbaDbQueryStoreOption: Fix DBNull issue and add missing Notes property

[andreasjordan]

Type of Change

• [x] Bug fix (non-breaking change, fixes # )
• [ ] New feature (non-breaking change, adds functionality, fixes # )
• [ ] Breaking change (affects multiple commands or functionality, fixes # )
• [ ] Ran manual Pester test and has passed (.\tests\manual.pester.ps1)
• [ ] Adding code coverage to existing functionality
• [ ] Pester test is included
• [ ] If new file reference added for test, has is been added to github.com/dataplat/appveyor-lab ?
• [ ] Unit test is included
• [ ] Documentation
• [ ] Build system

Notes was part of the default view, but not part of the object.

.Query("...") has returned NULL values as DBNull objects that could not be casted to int.

This needs to be tested with current version, not the old 2017 we have on AppVevor...