message: find room by alias in room pill
diff: @@ -16,6 +16,7 @@ limitations under the License.
  import AutocompleteWrapperModel from "./autocomplete";
  import Avatar from "../Avatar";
  +import MatrixClientPeg from "../MatrixClientPeg";
  const DPR = window.devicePixelRatio;
  @@ -221,12 +222,31 @@ export class NewlinePart extends BasePart {
  }
  export class RoomPillPart extends PillPart {
  - constructor(displayAlias, room) {
  + constructor(displayAlias) {
  super(displayAlias, displayAlias);
  - this._room = room;
  + this._room = this._findRoomByAlias(displayAlias);
  + }
  +
  + _findRoomByAlias(alias) {
  + const client = MatrixClientPeg.get();
  + if (alias[0] === '#') {
  + return client.getRooms().find((r) => {
  + return r.getAliases().includes(alias);
  + });
  + } else {
  + return client.getRoom(alias);
  + }
  }
  setAvatar(node) {
  + let initialLetter = "";
  + let avatarUrl = Avatar.avatarUrlForRoom(this._room, 16 * DPR, 16 * DPR);
  + if (!avatarUrl) {
  + initialLetter = Avatar.getInitialLetter(this._room.name);
  + avatarUrl = `../../${Avatar.defaultAvatarUrlForString(this._room.roomId)}`;
  + }
  + node.style.setProperty("--avatar-background", `url('${avatarUrl}')`);
  + node.style.setProperty("--avatar-letter", `'${initialLetter}'`);
  }
  get type() {
  