NIAD-3452: Schema validation issues when translating to XML

[chiaramapellimt]

What

I copied over all remaining files from test folders to main project so that now the references are properly sourced from within the implementation folders rather than trying to be fetched from the test side of things.

Why

Because the files lived in the test folders and were not being read by the implementation code.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Internal change (non-breaking change with no effect on the functionality affecting end users)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have updated the Changelog with details of my change in the UNRELEASED section if this change will affect end users

[github-actions]

Looks good. No mutations were possible for these changes.
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