LegacyBindingREST is only used for `bindings` resource. It is not
a subresource and that's why it is required to implement
`GetSingularName` function. However, there is no need to implement
this function for BindingREST because it is only used for binding
subresource.
That's why, this function statically adds GetSingularName for
LegacyBindingREST.
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