Unify bandwidth field name

[severindellsperger]

In the topology proto file topology.pb.go, we have the following properties:

UnidirLinkDelayMinMax []uint32                 `protobuf:"varint,24,rep,name=unidir_link_delay_min_max,json=unidirLinkDelayMinMax" json:"unidir_link_delay_min_max,omitempty"`
UnidirResidualBw      *uint32                  `protobuf:"varint,28,opt,name=unidir_residual_bw,json=unidirResidualBw" json:"unidir_residual_bw,omitempty"`
UnidirAvailableBw     *uint32                  `protobuf:"varint,29,opt,name=unidir_available_bw,json=unidirAvailableBw" json:"unidir_available_bw,omitempty"`
UnidirBwUtilization   *uint32                  `protobuf:"varint,30,opt,name=unidir_bw_utilization,json=unidirBwUtilization" json:"unidir_bw_utilization,omitempty"`
}

However, the property.go File in the JAGW service they are matched as follows:

MaxLinkBWKbps           = "MaxLinkBWKbps"
UnidirResidualBW        = "UnidirResidualBW"
UnidirAvailableBW       = "UnidirAvailableBW"
UnidirBWUtilization     = "UnidirBWUtilization"

In the documents.go file, the LsLink properties are defined as follows:

MaxLinkBWKbps         uint64
UnidirResidualBW      uint32
UnidirAvailableBW     uint32
UnidirBWUtilization   uint32

The mismatch of writing BW or Bw is confusing and should be unified.