Submission UI in case of only one receiver available could be simplified

[evilaliv3]

While thinking to some adopters that have only one receiver available I found that it would be interesting to optimize the submission interface by showing a different graphic disposition and without providing the user any selection of the user but simply showing his name along with its photo and the description.

[evilaliv3]

@vecna / @fpietrosanti: this would be interesting for example for the IJF use case and goes in the direction of providing the possibility for the single server instance to be reused along multiple indepentent users.

it would be useful both when there is effectively only one receiver per context, or when the url enforce to show only one receiver.

[fpietrosanti]

I like it, make sense if the user want anyhow to show the receiver step. Please consider this in th contxt of #841

[hellais]

+1