It is no safe to assumes that the mapstructure keys will contain all the keys because some config can be specified
with command line flags or literals.
This change allows us to remove the json marshal/unmarshal cycle for command line flags, which will allow
us to remove all of the hcl/json struct tags on config fields.
This will emit warnings about the configs not doing anything but still allow them to be parsed.
This also added the warnings for enterprise fields that we already had in OSS but didn’t change their enforcement behavior. For example, attempting to use a network segment will cause a hard error in OSS.
Dan Upton