Bug: card API 500 error when card descriptions are next to each other

[akhmerov]

Steps to reproduce the behavior

1. Create a card with two description entries side by side, like in the screenshot below.
2. Call /boards/{board_id}/cards on a corresponding board
3. Observe 500 response and an error Block2Card fail: invalid type for field 'contentOrder item' in the logs.

Screenshots (optional)

Edition and Platform

• Focalboard 7.5.2
• Mattermost Version: 7.5.1
• Database Schema Version: 95

[wuwinson]

cc @sbishel

[jespino]

@sbishel assigning it to you to reassign it.

[wuwinson]

This may get resolved with our new text editor in the future. Putting this Up for Grabs in the meantime.