Use optional chaining to avoid undefined monthly_monitor_report

[rhelmer]

References:

Jira: MNTOR-3848

Description

Use optional chaining to avoid monthly_monitor_report being undefined.

I believe that the problem here is that monthly_monitor_report can be null in the database if the monthly report has not run successfully for this account. I also believe we started getting more of these reports because the cron job that sends this email broke temporarily (it's now fixed), but there's still a possibility for this to happen for e.g. new users.

I did not add a unit test, but I did change the typescript types to reflect that this may be undefined.

How to test

The easiest way to to test locally is to ensure that monthly_monitor_report is null in the subscribers table.

Checklist (Definition of Done)

• Commits in this PR are minimal and have descriptive commit messages.
• Jira ticket has been updated (if needed) to match changes made during the development process.
• Jira ticket has been updated (if needed) with suggestions for QA when this PR is deployed to stage.

[github-actions]

Preview URL 🚀 : https://blurts-server-pr-5511-mgjlpikfea-uk.a.run.app

[Vinnl]

The question is: if the value can also be undefined, then why didn't TS warn us when we passed that into these components? So I traced that down to a couple of overeager type assertions, which I removed in #5521.

I'm also not 100% sure what the values of the checkboxes initialised with this value should be if it's undefined, but I would guess that they should actually be checked by default, rather than unchecked as they are now. My PR does that too.

(This PR is the target of that PR.)

[github-actions]

Cleanup completed - database 'blurts-server-pr-5511' destroyed, cloud run service 'blurts-server-pr-5511' destroyed