[Finishes #80390184, #80390220, #80390244, #69662090, #79918464]

 - image preview popup works for images in note/comment attachments as well (can download and add comment)
 - image preview and attachment image preview now available in other activity streams as well (tooltip on project card for recent comments and insights, sidebar on workfiles)
 - fixing styling/popup behavior for large images in show image preview popup
 - some styling changes to make it all look better
 - partial unit test updates, more pending