Don't check for only-emoji if there were none
Don't check for only-emoji if there were none

We were still running the emojione regex on all messages to
determine if they were *only* emoji (for the big emoji). This is
pointless on messages that we already know don't have emoji.

Also stop exporting unicodeToImage because it isn't used anywhere.

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