C18 power port type

[llamafilm]

NetBox version

v4.3.1

Feature type

Data model extension

Proposed functionality

Add a new power port type for C18. Part of IEC 60320 spec, similar to C14 but without ground.

Use case

This power port is common on audio devices

Database changes

No response

External dependencies

No response

[arthanson]

Should probably add both C18 and C17. Here is the wikipedia page: https://en.wikipedia.org/wiki/IEC_60320