FlashSuppressors - use next CBA's JM configs

[PabstMirror]

When merged this pull request will:

• Close Updating base class warnings on CBA >2.3.1 #3700 - Fix UBC errors and properly configure the 6.5mm weapons to use the right flash suppressors.

Quick version of how it works:

For most weapons we can just add it to the generic muzzle
eg class asdg_MuzzleSlot_762MG: asdg_MuzzleSlot { we add the *_B item which is 7.62mm and these should work on any mod using these joint muzles.

JR has the vanilla 6.5mm weapons using the 7.62mm muzzles, so we do

class compatibleItems: compatibleItems {
    ACE_muzzle_mzls_H = 1;
    ACE_muzzle_mzls_B = 0;
};

to disable our 7.62 attachment and enable our 6.5mm version.

ACE's 7.62mm still shows up in VA, but is not attachable (and exported itemName is wrong), problem with VA - CBATeam/CBA_A3#246 (comment)