chan: miss-attributed parent id on exploded comments

[azimut]

• When I explode a comment replying to multiple messages

  • I create 2 comments with the same ID

• When a new reply happens it might refer to only 1 of the new exploded comments

  • But right now we assign the parent to the first one exploded

• A partial solution might read the new reply for a quote in a <span> and

  • try to find another message with the same id that ALSO has the content of span