net-mgmt/py-hier-config: New port

Hierarchical Configuration is a Python library that is able to take a
running configuration of a network device, compare it to its intended
configuration, and build the remediation steps necessary bring a device
into spec with its intended configuration.

Hierarchical Configuration has been used extensively on:

• Cisco IOS
• Cisco IOSXR
• Cisco NXOS
• Arista EOS

However, any NOS that utilizes a CLI syntax that is structured in a
similar fashion to IOS should work mostly out of the box.