Rework `canSense` and `canSee` functions

[thokkat]

I reworked some functions based on testing:

• active perceptions are only perceived if npc has SENSE_SMELL or SENSE_SEE and canSee returns true, SENSE_HEAR does nothing
• passive perceptions only care for perc range and ignore senses and canSee
• canSee only cares for senses range
• npc_getnexttarget doesn't need line of sight.

This fixes Lares not stopping if guiding the player and shattered golem not attacking. To keep sneaking working while opening a chest walkbit is now used instead of bodystate for sneak mode testing.