Added in the API os-security-group-default-rules
This allows create, delete, list, and get (of individual rules) for
rules that will be pre-populated into the Security Group "default"
that is populated in all projects on creation.
These rules will not be applied retroactively, as it is designed
to allow the creation of a "reasonable" base-line set of sg rules.
The new rules live in a separate table that mirrors the relevant
structures of the security_group_rules table.
Added unit tests/API samples for the new API calls
Related to bp default-rules-for-default-security-group
DocImpact
Change-Id: I7ab51e68aff562bb869538197a0eca158fc3220c
59aaf1dff9