Allow channel names with a forward-slash / in them

[dhirschfeld]

When deploying internal conda packages my usual practice has been to namespace channels by their respective team name (which also corresponds to their organisation name in our GitHub Enterprise Server) - e.g. retail/dev, retail/prod

It appears this isn't supported when creating a channel:

quetz/quetz/tasks/indexing.py

Lines 271 to 274 in 6cdf96e

	raise NotImplementedError(
	"We can only handle channel_name/subdir/file.xyz OR"
	"channel_name/file.xyz"
	)

[dhirschfeld]

If I manually populate the database the channel listing appears to work:

...but drilling down into any channel fails with the frontend only looking for the first part of the channel name (i.e. channel_name.split('/')[0])

[dhirschfeld]

In my own implementation the namespaces were implemented as physical folders. If the backend storage supports folders that might also be possible in quetz?

Alternatively, I guess the channel name could be url-encoded in the backend... so long as that was transparent to the user
i.e. I'd want the UX to be mamba install -c seau/dev my-package not mamba install seau%2Fdev my-package