Consistent NPC reach range with trigdist

[ghost]

Summary

SUMMARY: Bugfixes "Consistent NPC reach range with trigdist"

Purpose of change

Fixes #16400

Describe the solution

Use same logic from ranged.cpp targeting ui for player reach attack to decide when an NPc can do the same.

Describe alternatives you've considered

N/A

Testing

spawned a monster , altered code slightly to make them stay still.
NPC would not do a 2-tile diagonal attack with a reach weapon, same as player cant, when circular distnaces are on.
They can still do one diagonal and one cardinal combo , and double cardinal reach attacks.
With circular distnaces off, both player and NPC can do their usual reach attacks.

Additional context

N/A