Adds hiding what you're wearing on your belt, adds the flag to a bunch of stuff (#86884)

We have the HIDEBELT flag but it isn't used anywhere and in fact is not
functional, so I added code to examine to enable it. I also threw the
flag onto a bunch of stuff -- primarily big billowy things, or stuff
like trenchcoats. This would include hiding guns, toolbelts, plant bags,
things of that nature. If you steal the Captain's saber and throw a
bedsheet on your head, you've pulled off the perfect crime.

Adds another way to be sneaky and immensely suspicious, increasing
paranoia when some guy wearing a big shapeless suit walks into the room.

![200w](https://github.com/user-attachments/assets/6faf3e9b-1a8a-4dec-ad4f-12792cf7eba0)
🆑 Bisar
add: Clothing can now hide what you're wearing on your belt.
/🆑

code/modules/bitrunning/objects/clothing.dm

@@ -8,3 +8,4 @@
 	name = "trenchcoat"
 	desc = "A long, black trenchcoat. Makes you feel like you're the one, but you're not."
 	icon_state = "trenchcoat"
+	flags_inv = HIDEBELT