Extend weapon functionality

[aske02]

This implements some new features for the weapon extension.

It has some features mentioned in #2677 and some extra ones.

New Functions

entity:hasWeapon(string classname)

entity:clip1Size()

entity:setClip1(number amount)

entity:clip2Size()

entity:setClip2(number amount)

entity:giveWeapon(string classname)

entity:giveWeapon(string classname, number noAmmo)

entity:selectWeapon(string classname)

entity:giveAmmo(number amount, string type)

entity:giveAmmo(number amount, string type, number hidePopUp)

entity:setAmmo(number ammoCount, string type)

entity:removeAmmo(number ammoCount, string type)

entity:removeAllAmmo()

entity:stripWeapon(string classname)

entity:stripWeapons()

New Events

event weaponPickup(Weapon:entity, Owner:entity) {
    
}

event weaponSwitched(Player:entity, OldWeapon:entity, NewWeapon:entity) {
    
}

New Convars
wire_expression2_weapon_ammo_set_enable
wire_expression2_weapon_ammo_give_enable
wire_expression2_weapon_give_enable

[vurvdev]

Feel like weaponEquipped should be weaponPickup instead, to not be confused with weaponSwitched.

As for permissions:

There definitely needs to be a convar for these functions, probably a separate one for each type of function:

1. Ammo giving/setting, removing shouldn't need anything.
2. Giving weapon

Also need to check if you WireLib.CanTool or E2Lib.isFriend with the target player for all of these functions.

For giving weapon also need to check https://wiki.facepunch.com/gmod/SANDBOX:PlayerGiveSWEP

Will do a more in depth review later

[aske02]

My bad hadn't really thought about permissions.
They should be added now.

[vurvdev]

Just need to fix the lints, check E2Lib.isFriend before CanTool and add convars to the functions I previously thought were fine to leave without any convars.