Cannot reliably sneak or steal in the sight of the NPCs siding with player
This is an accompanying issue for my open merge request !678 (merged) correcting the behaviour of detection in the line of sight of NPCs siding with the player.
In vanilla it's possible to train the sneak skill or know whether you're detected by other NPCs when you're in siding NPCs' line of sight, but currently in OpenMW the siding NPC counts as a normal NPC detecting the sneaking player, thus making it hard to reliably train or steal in their sight.
It is for example problematic in the Ra'Zhid's Dwemer Artifacts
quest when you need to steal the artifact from the chest in Hla Oad, Fatleg's Drop Off
but you're unable to know if you're detected by other NPCs as the siding NPC is standing next to you.
More discussion about the issue can be read here: https://discord.com/channels/260439894298460160/260443767482482688/823244522649550878