nidcpower and nifgen have incorrect data type for Import/ExportAttributeConfigurationBuffer

[bkeryan]

In the MI ImportAttributeConfigurationBuffer and ExportAttributeConfigurationBuffer functions, the configuration parameter is an array of bytes. The bytes contain a UTF-8 JSON string, but the API documentation doesn't document this, so it's appropriate for grpc-device to treat this parameter as an array of bytes.

nidcpower.proto and nifgen.proto incorrectly represent this parameter as repeated fixed64 configuration.

nidmm.proto, nifake.proto, and niscope.proto correctly represent this parameter as bytes configuration.

AB#2108035

[reckenro]

Both NI-DCPower and NI-FGEN .proto files updated so those arguments are now bytes configuration.

NI-DCPower ImportAttributeConfigurationBufferRequest and ExportAttributeConfigurationBufferResponse

NI-FGEN ImportAttributeConfigurationBufferRequest and ExportAttributeConfigurationBufferResponse