Add Kibana spaces security

[fbaligand]

It would be nice to have the ability to configure security access for each Kibana space:

• none: no access to one Kibana space
• read: read access to one Kibana space
• all: all access to one Kibana space

All that associated to one role in readonlyrest.yml

[coutoPL]

We have a new kibana.access: api_only and kibana.allowed_api_paths (see docs) that may help with solving the problem described in this issue.

[fbaligand]

Yes it could answer the need with /s/SPACE_ID/api/* URI.
That said, for read access for one space, this seems to be more complex to configure.

[sscarduzio]

it would be complex only if you want a user to have read only permission to a space in particular, it would be OK if a user is read only in general.

But yes, giving explicit permissions would require some research.