dm-4256 refactor practice card img placeholders for pagebuilder show and facility show

[PhilipDeFraties]

JIRA issue link

https://agile6.atlassian.net/browse/DM-4256

Description - what does this code do?

The main point of these changes is to make sure that practice card images always start as a background placeholder that is subsequently replaced with the practice card image. This had already been implemented everywhere but for facility and page-builder* show pages, this update adds it for said pages and refactors the involved methods a bit.

Testing done - how did you test it/steps on how can another person can test it

As logged-in admin:

1. Create a page-builder page and add and Innovations component with some innovations, view the page and verify the practice card images load and replace background images
2. Go to a few facility show pages that have created and adopted innovations, verify the same expected practice card image behavior as above.
3. Check for background-replacing practice card images on the practice search page, CRH show page, and VISN show page.

Screenshots, Gifs, Videos from application (if applicable)

Link to mock-ups/mock ups (image file if you have it) (if applicable)

Acceptance criteria

• [ ]

Definition of done

• Unit tests written (if applicable)
• e2e/accessibility tests written (if applicable)
• Events are logged appropriately
• Documentation has been updated, if applicable
• A link has been provided to the originating JIRA issue
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs

[camillevilla]

👏 good job extracting these functions! It's great that we can reuse our placeholder functionality.