Add Alternate functions accepting a regprocedure Param

[theory]

Instead of requiring that the schema, function name, and array of param types be passed separately, consider adding alternate functions for the function-testing assertions that accept a regprocedure parameter. Would be especially useful for function_privs_are(), so it could be called like so:

SELECT function_privs_are(
    'blanket.save_thingy( int, text, text, smallint, smallint, numeric )',
     'betty', 'EXECUTE', 'betty should have EXECUTE on save_thingy()'
);

The existing functions might be updated to use this version under the hood. Suggested by Jim Nasby.