Service links are broken when manually editing content (i.e in Element)

[aofn]

Describe the bug
Pad links or sketch links are broken when the link inside the room was edited.

To Reproduce

• Create an /etherpad pad
• find the corresponding room in Element and edit the message. (make sure link is still valid)
• open the pad in /spaces

Expected behavior
Link should not be broken after editing (as long as link is till valid)

Screenshots

Possible fix

check if the object has a m.new_content key and if so return it otherwise return body

{
   "msgtype":"m.text",
   "body":" * http://spacedeck.localhost/spaces/8f51b463-a9a2-46f8-8646-d037f8438984",
   "m.new_content":{
      "msgtype":"m.text",
      "body":"http://spacedeck.localhost/spaces/8f51b463-a9a2-46f8-8646-d037f8438984"
   },
   "m.relates_to":{
      "rel_type":"m.replace",
      "event_id":"$VNqjjshe1Be75fLYAvqDdd0MRyhvBJXpFZaE3o9MFWs"
   }
}