fix: handle copying app methods (#4491)

[ColinBuyck]

This PR addresses bloom-housing#4490

• Addresses the issue in full
• Addresses only certain aspects of the issue

Description

This PR updates the duplicate function in the listing service to transform the application methods array to how the listing create function expects it.

How Can This Be Tested/Reviewed?

Test copying a listing with no paper app, paper app selected but not uploaded, one paper app, multiple paper apps... and ensure that the listing and assets are copied over without error.

Author Checklist:

• Added QA notes to the issue with applicable URLs
• Reviewed in a desktop view
• Reviewed in a mobile view
• Reviewed considering accessibility
• Added tests covering the changes
• Made corresponding changes to the documentation
• Ran yarn generate:client and/or created a migration when required

Review Process:

• Read and understand the issue
• Ensure the author has added QA notes
• Review the code itself from a style point of view
• Pull the changes down locally and test that the acceptance criteria is met
• Either (1) explicitly ask a clarifying question, (2) request changes, or (3) approve the PR, even if there are very small remaining changes, if you don't need to re-review after the updates