tests for broken binary deprecated behavior

bson_iter_binary and bson_append_binary don't appropriately write or
read BSON_SUBTYPE_BINARY_DEPRECATED.  These tests test for that
functionality.

Specifically we don't add or handle the redundant leading int32 payload
fixed handling of binary SUBTYPE_DEPRECATED

didn't appropriately handle the deprecated binary format (in particular
the redundant int32).  Fixing that up
Merge remote-tracking branch 'origin/fix_dep_bin'
style: cleanup.