Note - DirectoryServerTableViewCell:
Presently the thirdPartyProtocolInstance.icon is not a Matrix Content URI. We could not use here MXKImageView setImageURI method
without breaking the instance icon rendering. We use the deprecated interface until this point is fixed on the server side.
- Update the room display name and its avatar url when the Room Summary is updated on state events change (see `[session: updateRoomSummary: withStateEvents:]`).
- Store the riot display room name and its avatar url in the Room Summary.
- Add a new category `MXRoomSummary+Riot` to handle avatar display.
TODO: Increase file store version in `MXFileStore.h`.
