fix copy attachment with invalid properties

[deepikaSingh2711]

Describe your changes

Previously, invalid attachments were copied anyway, causing data inconsistencies. Attachments with incompatible properties are now rejected when copying to a target entity that doesn't support those properties.

Behaviour

Valid attachments → Copied normally
Invalid attachments → Not copied, warning shown, cleanup done
Mix of both → Valid ones copied, warning for failures
(new target entity) Invalid attachment -> Not copied, warning shown (if user click on discard draft) entity will be deleted

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)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist before requesting a review

• I follow Java Development Guidelines for SAP
• I have tested the functionality on my cloud environment.
• I have provided sufficient automated/ unit tests for the code.
• I have increased or maintained the test coverage.
• I have ran integration tests on my cloud environment.
• I have validated blackduck portal for any vulnerability after my commit.

Upload Screenshots/lists of the scenarios tested

• I have Uploaded Screenshots or added lists of the scenarios tested in description

https://github.com/cap-java/sdm/actions/runs/26169578053

https://github.com/cap-java/sdm/actions/runs/26169595330