Improve handling of change requests

[phavekes]

This issue is imported from pivotal - Originaly created at Sep 9, 2024 by andreklaver

Change request are not always 100% relevant. It would be nice to be able to select the fields to accept or reject.

Use the Import XML/JSON as an example. There, you can select or deselect fields to import. There is an overview of 'Current Value' and 'New Value' (current metadata and the imported metadata) when you confirm/import the changes.