Disambiguate display name if it contains a mxid
Disambiguate display name if it contains a mxid

Fixes https://github.com/vector-im/riot-web/issues/1811

Signed-off-by: Stefan Parviainen <1c44db95109f1e617f297f1f2e2c9ae3e916b412@iki.fi>

krombel/matrix-js-sdk,krombel/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,krombel/matrix-js-sdk