DSR layer-protocol-qualifiers for rates above 400G are missing

[roshan-joyce-fujitsu]

Right now, tapi-dsr.yang defines only up to 400G for GigE.
However it defines upto 3200 for FC (Fiber channel?)

    identity DIGITAL_SIGNAL_TYPE {
        base tapi-common:LAYER_PROTOCOL_QUALIFIER;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_GigE {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_10_GigE_LAN {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_10_GigE_WAN {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_40_GigE {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_100_GigE {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_200_GigE {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_400_GigE {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    identity DIGITAL_SIGNAL_TYPE_FC_100 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_200 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_400 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_800 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_1200 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_1600 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    identity DIGITAL_SIGNAL_TYPE_FC_3200 {
        base DIGITAL_SIGNAL_TYPE;
        description "none";
    }
    }```

CC: @nigel-r-davis @bcjohnso99 

[bcjohnso99]

Note that OTUCn rates are also missing from dsr-types

This exists for ODUCn to prevent the need to list all rates:

• odu-cn-csep-ttp-pac   Includes number-of-odu-c

And this exists for OTUk

• otu-csep-ttp-pac

We'd need to add an equivalent for OTUCn:

• otu-cn-csep-ttp-pac Includes number-of-odu-c