Report does not scroll exactly to unread message when chat contains images

[rlinoz]

Follow-up from PR #51366 review:
#51366 (review)

Issue:
When the chat contains an image, the report does not scroll exactly to the unread message. This may be because the thumbnail size is calculated after linking to the unread message.

Original evidence:
https://github.com/user-attachments/assets/ce8f1749-3867-46e4-bbcf-466b93df58f5

Issue Owner

Current Issue Owner: @chrispader

[chrispader]

This might get fixed by this PR, since the underlying initial rendering logic changes fundamentally.