Lightbox: Added Button to jump to current image within the conversation

[findus]

First time contributor checklist:

• [x] I have read the README and Contributor Guidelines
• [x] I have signed the Contributor Licence Agreement

Contributor checklist:

• [ ] My contribution is not related to translations.
• [x] My commits are in nice logical chunks with good commit messages
• [x] My changes are rebased on the latest main branch
• [] A npm run ready run passes successfully (more about tests here)
• [x] My changes are ready to be shipped to users

Description

Adds a "jump to conversation" button to the Media-Lightbox to jump to the position in the conversation where the image was used.