Social network name of a channel (@...) doesn't behave well with accents/special characters

When creating a channel, the social network name is created automatically based on the name you give to the channel. Spaces, special characters and accents are escaped. For the latter ones, they should be replaced by their non-accented versions. Of course the social network name can be modified manually, but the user experience is not so great... é -> e è -> e etc.

If possible, it might be good to do this language-wise, based on the app language setting. For instance in German, ä must be translated to ae (and ö->oe, ü->ue). Not sure if other languages are concerned though, it might be a very specific case...