fix: add null check for csv export

[ludtkemorgan]

This PR addresses: This slack thread and This comment

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

Description

Due to bad data in staging there are a few listings where there is non applicant attached to applications. When a user attempts to export the applications for the listing these are tied to it crashes the backend.

This PR adds a null check to make sure if this data exists it won't break anything

Also there was a missing space in the updated content of the rental opportunity email

How Can This Be Tested/Reviewed?

Have an application and remove the applicant_id from it in the db. You should then be able to properly export the applications.

This is blocking the release so no tests have been created, but long term we should add tests for this functionality

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

[ColinBuyck]

Is this aspect of this issue also blocking?

[ludtkemorgan]

@ColinBuyck that has been added!

[ColinBuyck]

Got this error when trying to edit

[ColinBuyck]

LGTM 🧼 talked offline and null checks associated with editing the application will be handled in another ticket