Allow single point sling to utilize PALS/MOLLE attach system

[PlutusPleion]

Summary

None
"allow single point slings to attach to PALS/MOLLE compatible gear like load bearing vests"

Purpose of change

*Had to close previous #55241 because I didn't make a branch to do the pull request for. Made a branch now and had to make new pull request.

1. Player choice: Give the player the customization and choice of attaching the sling to their vest
2. Realism: We attach single point slings to vests
3. Balance: Currently the survival harness is by far the most efficient holder since most long guns can only be holstered to single point slings and survival harness. Single point slings can be used in conjunction with PALS holders but at the cost of much more encumbrance. This has the added benefit of freeing up "hang from front" strapped slot, while limited, adds to making pals/molle vests competitive.

Describe the solution

Allow single point slings to be attached to PALS/MOLLE capable gear such as load bearing vests and ballistic vests.

Chose the tag variant which takes up the most space(3) PALS_LARGE instead of medium or small for balance.

Describe alternatives you've considered

• Nerf survival harness by adding more encumbrance to be in line with single point slings used with PALS gear

Testing

• Check to see if it attaches (pass)
• Check to see if it can detach (pass)
• Check to see if a player can place a gun in the pocket (pass)

Additional context

[bombasticSlacks]

Hey based on this and our discussion from before I did some more rigorous testing and you are right that the PALS gear wasn't appealing with current values. I've done a balance PR that should meet in the middle a bit. Survivor Harness Sling is a bit worse but the PALS gear is much better.

#55294