Use components for calls for evidence

[andysellick]

⚠️ This repo is Continuously Deployed: make sure you follow the guidance ⚠️

What

Output attachments in call for evidence pages using the data from the content item, rather than the pre-rendered markup from the content item, and apply GA4 tracking to those attachments that contain Details elements.

This follows on from the work to convert publications in the same manner: #3058

Attachments on consultation pages can occur in two places, so this is a bit more complex than publications, although some of the code and tests have been copied from that previous work.

Example pages to test with:

• open call for evidence
• call for evidence outcome
• closed call for evidence

Why

This work is for two reasons:

• to convert the rendering of attachments to using components so that tracking can be added to Details elements within attachments (for the 'Request an accessible format' element)
• to generally move away from the use of pre-rendered markup passed through content items

Visual changes

None, except PDF custom thumbnails are intentionally no longer shown.

Trello card: https://trello.com/c/tcTN1jbu/28-update-rendering-of-govspeak-attachments

[KludgeKML]

LGTM