Resort to greedy join ordering after some number of pairs considered

[scsmithr]

glaredb/bench/standard/many_base_relation_join_14.bench

Lines 3 to 16 in e76bfa1

	# TODO: Produce too many orders
	# PLANNING PROFILE DATA
	# Step Elapsed (micro)
	# resolve_step 86
	# bind_step 56
	# plan_logical_step 7
	# optimizer_step 15895342
	# expression_rewrite 8
	# filter_pushdown_1 308
	# limit_pushdown 2
	# column_pruning 18
	# join_reorder 15895002
	# plan_intermediate_step 56
	# plan_executable_step 59

Current join reordering considers all possible pairs with no early stopping.

We should stop and fall back to greedy once we've considered some number of pairs.