Currently ironic explicitly or implicitly sets the API urls
for most services in the config.
This is quite fragile and we should move to discovery from
the keystone catalog eventually.
To support this, this patch registers `keystoneauth1.adapter.Adapter`
options to all config sections for service clients auth.
Among others it exports `interfaces` option that we set to
['internal', 'public'] by default.
Other exported options are `service_type`, `service_name`, `region_name`
and `endpoint_override`.
The latter will eventually be used by all clients to specify a specific
endpoint to use (for example in noauth mode).
Effectively this patch starts to move all clients code to load client
configuration from config for all of auth, session and adapter.
The first to move is [service_catalog] section, with [conductor]api_url
option being deprecated in favor of [service_catalog]endpoint_override.
A sane default of 'service_type' = 'baremetal' is set for this config
section as well.
More patches moving other clients to consume these new options and
deprecate some other options will follow.
Change-Id: I1283ef3b4d736ac089df0cc74a5850a93b24b6ab
Partial-Bug: #1699547
Related-Bug: #1699542
308e414a57