Add automatic precaching of model textures, groups and sounds

[Arkshine]

An attempt to allow automatic precaching for model textures (*T.mdl) / groups (*01.mdl, etc.) and weapon sounds, similar to what does already ReHLDS.

Few remarks:

• Small QoL mainly for convenience and to trigger less crash
• This targets only vanilla engine as it exists in ReHLDS. It would have been ideal to have this in the engine, but considering GoldSrc is in maintenance mode only, new features are not going to happen.
• The reason that the code is global and located in ServerActivate is to allow the modules as well.
• Unlike ReHLDS, there is no cvar to choose to precache weapon sounds. Not sure if necessary. Why is there a cvar?
• Actually, do we need cvars for people to opt-in automatic precaching?

To be discussed.

[WPMGPRoSToTeMa]

The code relies on a temporary fake entity because of afaik, unless done manually, there is no direct way other than using pfnGetModelPtr which require an edict (internally, it retrieves model_t* from pev->modelindex).

Then maybe just create a variable with the edict_t type? I think we can rely on implementation details here.

[Arkshine]

You're right, not sure why It did not occur to me.

Any others suggestions or thoughts on it? What about the cvars?

[IgnacioFDM]

I think cvars should exist. There are things I intentionally don't precache because I don't need/want clients to download, like some weapon sounds.

[PartialCloning]

Missing *T.mdl results in the server crashing, missing sounds don't. Weapon sound precache or precaching sounds attached to models should have a cvar and more importantly should be opt in, not opt out. Like REHLDS.

This is better suited to a plugin than a built in feature in AMXMODx. Expect zombie server owners to complain about the new amxmodx crashing their server because of too many resources, where as the old one worked fine.

[Arkshine]

Well, we can go with upgrading precache_model native, and adding precache_weapon_sound native for example. For modules, adding MF_PrecacheModel and MF_PrecacheSound or something like that. It would be more specific and no config needed like cvars.

[WPMGPRoSToTeMa]

and adding precache_weapon_sound native for example.

@Arkshine it's not only for weapons.

[Arkshine]

Then I guess precache_model_sound :P.

Anyway, please give feedbacks, should we go with the natives way?

[HamletEagle]

Automatically precaching model sounds shouldn't be the default behavior. I think we should go with the native because it would allow to decide individually for each model unlike a cvar which would be global.

[justgo97]

Yeah, this should be just natives and shouldn't change any HLDS behavior

[Arkshine]

Alright.

[WPMGPRoSToTeMa]

Maybe we should go with both cvar (however we can add it later) and native?