Our existing hostname policy configs use JSON. We would like to switch to YAML
to match the rate limit policy configs and to support commenting/tagging
entries in the hostname policy.
The PA is updated to support both JSON and YAML while we migrate the existing
policy data to the new format. To verify there are no changes in functionality
the existing unit tests were updated to test the same policy expressed in YAML
and JSON form.
In integration tests the `config` tree continues to use a JSON hostname policy
file to test the legacy support. In `config-next` a YAML hostname policy file
is used instead.
The new YAML format allows separating out `HighRiskBlockedNames` (primarily
used to meet the requirement of managing issuance for "high risk" domains per
CABF BRs, mostly static) and `AdminBlockedNames` (used after administrative
action is taken to block a domain. Additions are made with some frequency).
Since the rate at which we change entries in these lists differs it is helpful
to separate them in the policy content.
Daniel McCarney