Improving the Spy traitor

[Katzen]

The first change is in!

Reward tiers (minimum and maximum TC value)
Tier 1
value_high = 4
value_low = 0
Tier 2
value_high = 6
value_low = 3
Tier 3
value_high = 8
value_low = 5
Tier 4
value_high = 99
value_low = 7

Old logic:
Limbs - 7% chance of being Tier 3, 93% chance of being Tier 2.
Personal items - 10% chance of being Tier 4, 90% chance of being Tier 1-3.
Big station objects - 15% chance of being Tier 1-2, 85% chance of being Tier 1.
Photos - Tier 1
Station items - 10% chance of being Tier 1-2, 90% chance of being Tier 1.

New logic:
Limbs
HOS/Captain- Tier 4
Heads/security - Tier 3
Other jobs - 7% chance of being Tier 3, 93% chance of being Tier 2.
Personal items
HOS/Captain - Tier 4
Heads/security - 10% chance of being Tier 4, 90% chance of being Tier 2-3.
Other jobs - 10% chance of being Tier 4, 90% chance of being Tier 1-3.
Big station objects
Hard - Tier 2-3
Medium - Tier 1-2
Easy - Tier 1
Photos - Tier 1
Station items
Hard - Tier 2-3
Medium - Tier 1-2
Easy - 10% chance of being Tier 1-2, 90% chance of being Tier 1

How much items are worth was basically made up by me so please comment. The idea is that if an item is hard to get (secure area/important person) it's worth more.
The biggest change is really to small items and the big objects you can't move which before were very likely to be low value.

From line 344 you can see how much things are worth, 1 is the least, 3 is the best: https://github.com/goonstation/goonstati...ft.dm#L344

I will start next on sorting all the rewards into three buckets, standard, good and great and potentially excluding a few of the worst rewards.
TC cost doesn't directly translate into being good for spy. Somehow need to do this without making the common rewards worse and not spoiling the random element.