VOTE-1064 basics block dynamic headings

[SamiraMSadat]

Jira ticket

https://cm-jira.usa.gov/browse/VOTE-1064

Description

In the basics modules taxonomy, change the heading levels dynamically based on whether the basics block heading is set.

Deployment and testing

Pre-deploy

1. lando retune

QA/Test

1. Sign into the CMS locally
2. Go to http://vote-gov.lndo.site/register and edit the basics block to have a heading.
3. Confirm the Basics Block heading is h2 and the module subheadings are h3.
4. Remove the Basics Block heading
5. Confirm the module subheadings have changed to h2
6. Repeat steps 2-5 for Spanish. You might have to create the new translation if it doesn't exist yet.

Checklist for the Developer

• A link to the JIRA ticket has been included above.
• No merge conflicts exist with the target branch.
• Automated tests have passed on this PR.
• A reviewer has been designated.
• Deployment and testing steps have been documented above, if applicable.

Checklist for the Peer Reviewers

• The file changes are relevant to the task objective.
• Code is readable and includes appropriate commenting.
• Code standards and best practices are followed.
• QA/Test steps were successfully completed, if applicable.
• Applicable logs are free of errors.