Subscriber Services: PON and DSL G.fast DSL Forum VSAs CLI changes

We now support G.fast and PON TLVs in ANCP port status messages and PPPoE-IA tags according to the IETF draft extension to RFC 6320, Protocol for Access Node Control Mechanism in Broadband Networks. The CLI for traffic shaping based on DSL-Type (0x91) TLV or PON-Access-Type (0x92) TLV is now located in the dsl and pon stanzas at the [edit system access-line] hierarchy level. The previously supported options are deprecated but redirect for a limited time to the new CLI. A new type option enables support for any future DSL or PON types by specifying the access line type value from the DSL-Type (0x91) TLV or PON-Access-Type (0x92) TLV.