mgr/deepsea: return ganesha and iscsi endpoint URLs

mgr/deepsea: return ganesha and iscsi endpoint URLs

This updates describe_service() to include nfs and iscsi services
(deepsea internally refers to these as "ganesha" and "igw" roles).
Additionally, if deepsea sets any of container_id, service, version,
rados_config_location, service_url, status or status_desc, these will
come through now too.

This relies on https://github.com/SUSE/DeepSea/pull/1606 for the new
functionality, but if run against an older version of deepsea, it will
continue to operate as it did before, it just won't include
rados_config_location or service_url data.

I've also updated the caching in describe_service() so that if the
cache needs filling, it just requests all services from DeepSea, caches
everything, then does filtering on the results.  Previously, if the
cache was empty and only one service type was requested, the cache
would then *only* include that service and no other items, so subsequent
requests for different service types would return nothing until the
cache expired.

Fixes: https://tracker.ceph.com/issues/39095
Signed-off-by: Tim Serong <tserong@suse.com>