API: Deprecate binary sortkey input in ApiQueryCategoryMembers

API: Deprecate binary sortkey input in ApiQueryCategoryMembers

Depending on what method is being used to encode the binary sortkeys,
it's very possible that sending a binary value will be mangled by
WebRequest's UTF-8 normalization.

Rather than trying to fight it, let's just do what should have been done
in the first place when r86257 changed sortkey output to hex-encoded.
Too bad now we have to deprecate the old params and add
differently-named new ones instead of piggybacking on the original
breaking change.

Bug: 70690
Change-Id: I5a031e980967cbe574dddc261d56604cecc7147a