In mobile view of meetings module, participants section should be removed and move to the details section.

* Mobile, the participant section is removed completely and a "{n} Begin of the insertionparticipants [Show all](https://community.openproject.org/#)"End of the insertion Begin of the deletion participants"End of the deletion line is added to the Meeting details.
* After clicking on Begin of the insertion"Show all",End of the insertion Begin of the deletion "{n} participants" button,End of the deletion it shows the existing participant modal Begin of the deletion
* A separate "Add participant" button is added, showing the same modalEnd of the deletion

Begin of the insertion<img class="op-uc-image op-uc-image_inline" style="width:270px;" src="/api/v3/attachments/80196/content">

https://www.figma.com/file/cJDhzOmYMstUNRS3EmgqZ0/Meeting-Module-co-creation?type=design&amp;node-id=0-1&amp;mode=design&amp;t=PLqI4giy6Rrtg2hp-0End of the insertion Begin of the deletion Reuse existing participant modal for implementing this.End of the deletion