responses: Use BooleanCompat for forward-compat too
query_globalblocks_target was failing because GlobalBlocks switched the empty string booleans to real booleans (8262751835dfe). We can use the BooleanCompat trick from mwtitle that handles both real booleans and the empty string so we can handle the legacy case as well as when it gets fixed in MediaWiki.
Add some better debug output for when tests fail that make it easier to recreate the API queries in your browser.