added BHCE support

[m4lwhere]

Added support for BHCE.

BHCE operates differently when marking owned users. Instead of a specific bool property, owned objects are now tracked within a system_tags property as a space delimited string. This is updated to reflect that by searching for and accessing that property in this way. I've also written a check which will concatenate owned to the system_tags property if another entry exists, as to make sure we don't overwrite anything important (such as an object with admin_tier_0 set).

Additionally, I've added .upper() to the user domain, as I was entering them in lowercase. Not necessarily a BHCE requirement, but definitely a QoL.