SHS-5988: Fix empty heading on postcards without title

[mariannuar]

READY FOR REVIEW

Summary

Fix empty heading on postcards without title

Urgency

medium

Steps to Test

1. Go to https://hs-traditional-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com/components/collections-0/collections-postcards/vertical-cards/vertical-cards-raised-cards
2. Scroll down to Vertical Postcards with Title, Image and Link in a Collection and Vertical Postcards with Title and Image in a Collection (first of the third row of cards)
3. Confirm that if there isn't a title in the card, there isn't an h2 in the markup
4. Please test this in other cards (in views too) by editing the card and removing the card title

PR Checklist

• PR Checklist
• Humsci Basic PR Checklist

[ahughes3]

Tugboat has finished building the preview for this pull request!

Links:

• https://pr1699-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com
• https://hs-colorful-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com
• https://hs-traditional-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com
• https://english-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com
• https://history-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com
• https://west-hjupmoiykro8of7nlzyvwahjo999gbjf.tugboatqa.com

Dashboard:

• https://dashboard.tugboatqa.com/6761d39e919fa9b3e74c9b4b

Visual Diffs:

• https://dashboard.tugboatqa.com/6761d39e919fa9b3e74c9b4b/visualdiffs

[cienvaras]

@mariannuar LGTM!

@ahughes3 Ready for you to review

[cienvaras]

@ahughes3 Please take a look at this comment before approving the PR. The Chemistry site is not in Tugboat, but the existing links in the cards break after applying this fix. I think that the fix is still necessary, but descriptive titles should be added if they want to keep the links working.