Allow the bots to use lock-on weapons

[Firjens]

Requested feature

Currently, bots only use grenades and RPG (or MSAW) against vehicles and vehicles.

It'd be nice to see that each engineer either spawns with a RPG-like weapon, a JAVELIN-like weapon or a Stinger-like weapon and they can use it on vehicles like players are able to do.

For RPG-like weapons, no change is requested as the way they work is good.

For the locked-on missile launchers, when a bot has an armored vehicle or other object that can be locked on using the missile launchers, they use their weapon against that vehicle by initially locking on the vehicle and firing when the lock on is completed.

Additionally, having a time between lock-on and actual firing gives it a bit more realistic variant
When the vehicle is getting out-of-range, the bot has to follow that vehicle but it shouldn't be too strict (example; when a plane is flying over at low altitude and is going very fast, it's more difficult to track it than when it's a helicopter flying nearby).
A configuration to allow server owners and developers to fine-tune this, by including an option to enable or disable this, a minimum and maximum lock-on time (when a missile launcher is locked on a vehicle, having it not fire directly makes it more realistic), etc.
A configuration to allow a maximum amount of JAVELIN and Stinger per team (if there are a maximum of 3 engineers and they all 3 have stingers, it's going to cause for a bad time for any plane).