support matrix.to links (#1849)

* support room via server params and eventId

* change copy link to matrix.to links

* display matrix.to links in messages as pill and stop generating url previews for them

* improve editor mention to include viaServers and eventId

* fix mention custom attributes

* always try to open room in current space

* jump to latest remove target eventId from url

* add create direct search options to open/create dm with url

src/app/components/editor/slate.d.ts

@@ -29,6 +29,8 @@ export type LinkElement = {
 export type MentionElement = {
   type: BlockType.Mention;
   id: string;
+  eventId?: string;
+  viaServers?: string[];
   highlight: boolean;
   name: string;
   children: Text[];