I didn’t find a list, but I did find a useful site for determining which abilities are and which are not. WowDB lists each ability and includes the cooldown catagory:
https://www.wowdb.com/spells/class-abilities/demon-hunter/specialization/havoc
For example ‘Eye Beam’ in patch 9.0.1 did not have a GCD:
https://www.wowdb.com/spells/343311-eye-beam
What I was able to do for Havoc DH was go through all of the abilities and list which ones had GCD and which didn’t.