cleanup series of webxdc info messages (#3395)

* clarify webxdc reference wrt info-messages

* add from_id parameter to add_info_msg_with_cmd()

* flag webxdc-info-messages as such

* set from_id to sender for webxdc-info-messages

* test additional webxdc info properties

* do not add series of similar info messages

instead, if on adding the last info message
is already from the same webxdc and sender,
just update the text

* test cleanup of webxdc info messages series

* update changelog

* make clippy happy

there is no real complexity in the args,
so allowing one more arg is probably fine.

if really wanted, we can refactor the function in another pr;
this pr is already complex enough :)

* use cleaner function names and comments

* clarify CHANGELOG

src/peerstate.rs

@@ -302,6 +302,7 @@ impl Peerstate {
                         timestamp_sort,
                         Some(timestamp),
                         None,
+                        None,
                     )
                     .await?;
                     context.emit_event(EventType::ChatModified(*chat_id));