MINOR: filters: Expose global filter ordering through the CLI

MINOR: filters: Expose global filter ordering through the CLI

Accept global for show filter classes and show filter instances, and show
all three orders when no direction is selected. Include global in single
instance details. Traverse unflattened class references for defaults as
well as flat lists for regular proxies.

Share class dumping across the three orders and instance dumping across
flat lists and class-reference trees. Reset separators for each order and
emit one complete line per order, including empty lists.

Extend the regression test to check the global registry order, independent
request/response orders, reordered and inherited instances, defaults,
lookup without double counting, enabled state and invalid CLI directions.