add suffixes from provider to room and @room completions
add suffixes from provider to room and @room completions

this prevents the @room not working when not typing an extra space

matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk