WIP: stack/erp5/instance-wcfs: Update NEO zurl

Hello @kirr,

this is the SlapOS part of https://lab.nexedi.com/kirr/neo/merge_requests/3 and the implementation of what we discussed at https://lab.nexedi.com/levin.zimmermann/neoppod/commit/573514c6e8ecf0f1c28a821f9db037850a711472#note_184653.

I hope the commit message summarizes it correctly:

With https://lab.nexedi.com/kirr/neo/merge_requests/3 we changed the NEO scheme from

neo(s)://[credentials@]master1,master2,...,masterN/name?options

to

neo(s)://[credentials@]master1,master2,...,masterN/name?server_options#client_options

This change needs to be applied to the NEO URL constructor in SlapOS which parses the URL to wendelin.core. Furthermore this patch drops SlapOS NEO options, which don't belong to NEO API options (_ca, _key, _cert [1]), in order to stabilize WCFS.

[1] https://lab.nexedi.com/nexedi/slapos/blob/8e6f4101/software/neoppod/instance-neo-input-schema.json#L62

It's still WIP because I'm waiting for the last SlapOS integration test results.

It would be nice if we could wait for further process in https://lab.nexedi.com/nexedi/neoppod/merge_requests/18 before applying this MR. If - for instance - we revert how SSL parameters are parsed currently, this could also be applied within the same MR and we wouldn't need to rework this SlapOS instance file again & again. But because it's not that complex to do this, I think it's also okay to apply this now.

Best, Levin