methodtable total searches need to consider all binding partitions

[vtjnash]

With the binding partition work, our various methodtable visitors (e.g. staticdata, ml_matches, disable_method, Test, REPLCompletions) might fail to correctly find all types and thus fail to find all methods as may be required for correctness. We need to update our many different copies of the methodtable visitor logic to look specifically at all BindingPartitions of all Bindings in all worlds and not to look at the output of names anymore to enumerate them.

This is also a possible bug for any other consumer of names (e.g. summarysize), though there are quite few of those uses currently in base and stdlib.