Grenade overhaul part 2, the quest for more havoc

[BonniePandora]

About the pull request

Overhauls the grenade packet icon system, they now share a similar one to how grenade boxes work. Packets once emptied can be folded flat and M40-hull type ones now hold five grenades as standard. Ones that hold M15s, SEBBs, etc etc, retain a capacity of three.
The M60 WPSI & M77 HIAM have both recieved dual-fusing functionality, detonating on impact if fired from a UGL. Beware dinking something in the face with one of those loaded. WPSI now generates flaming shrapnel on detonation to simulate chunks of phosphorus landing on unlucky bastards.
All smoke-producing grenades & the new WP mortar shell have longer-lasting smoke effects.

Two new grenades added, along with corresponding packets. No grenade boxes for either (yet?)

• M230 LLRB grenade; a less-than-lethal baton round that will shatter on impact after hitting a target, imparting significant knockback to them and putting them on their arse for a short spell. Mostly blue-plastic body.

• M72A2 HIPF starshell grenade; a para-flare grenade for marines to light up areas. Description flavoured as being an advancement on the tech-manual mentioned A1 model and capable of embedding into roofs where it illuminates too. (I did not wish to deal with the jank of roof code and such, ergo this solution). Yellow cap, yellow band on the hull to designate it as launcher-fired only. Available from the gear vendors aboard the Garrow & Rover

Not exactly a grenade, but I did also add a new WP mortar shell for maximum warcrims & Spec Ops The Line LARPing.

Integrates the changes put forth in #597 with permission from Andro too.
Cliff notes of that;

• UPP get a rifle-mounted GL & impact rounds to load into it
• UPP smoke grenades
• Adjustment of grenade priming sounds so that non-M40 hull grenades have a pin-pull sound when primed

Explain why it's good for the game

Catches the last of the changes I wanted to impliment grenade-wise without feature-creeping the prior grenade overhaul PR.
Packet folding is just... Why wasn't it like that from the get-go when they were added? WHY?
The two new grenade types offer up both a less-than-lethal option & illumination round for marines to use.

Testing Photographs and Procedure

Tested locally, all works as intended. Compiles without issue.

Screenshots & Videos

Changelog

🆑
add: Adds the M230 LLRB & M72A2 HIPF grenades and a WP mortar shell
add: UPP smoke grenades, along with a rifle-mounted grenade launcher & impact rounds for it.
admin: Added the WP mortar rounds to the fire support menu
qol: Grenade packets can be folded flat once emptied
qol: Packet sprites overhauled with overlays & such on a base sprite
balance: The M60 WPSI & M77 HIAM now both have dual-fusing functionality. M60 WPSI generates shrapnel on detonation
balance: Smoke effects from grenades and the new mortar shell linger much longer than they did previously.
spellcheck: 'box of flashlight' -> 'box of flashlights' in gear vendor
imageadd: Sprite for the M72A2 grenade & WP mortar shell
maptweak: The Chapev recieves one rifle-GL per squad along with rounds for it in the vendors, & some boxes of smokes grenades in the cargo bay.
/:cl:

[cm13-github]

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[cm13-github]

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