[core] new luautil function: getEntitiesInRange()

[MowFord]

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• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

Sparked by this comment, I've created a more generic binding for finding entities in range of an entity, using the existing CTargetFind class.

I'm putting this in draft mode while I test it, but preliminary testing seems to work (the benefits of using pre-existing systems)

This PR lays some groundwork:

• Creates a missing enum essential to skills/abilities: AOE_TYPE
• Copies all targetfind enums into lua space, with some comments about their caveats

The PR's main change: getEntitiesInRange()

• This binding first does basic checks and returns an empty table if anything essential is missing with the parameters
• It then calls a PAI->Targetfind flow similar to spells or mobskills
• the return is always a table, empty if no targets were found within the given targetfind parameters

Steps to test these changes

[MowFord]

targetfind is funny about conals in that it always adds the primary target my work in #5745 will make it more reliable if one needed to use this binding for raw conal findings, but in general the binding seems to work well.

It's written explicitly to be used for Dark Ixion, so I'm going to start poking at it there

[MowFord]

I've done some testing and it seems to do what's on the tin here. Ixion functions with the new binding, but will benefit greatly from the extra TARGETTYPE in #5745

[zach2good]

If this is targetfind-based, it can find more than players depending on the flags, no?

[MowFord]

Good catch, yes. Started from my old binding. I'll update the variable

[MowFord]

Done

[zach2good]

auto getEntitiesInRange(CLuaBaseEntity* PLuaEntityTarget, sol::variadic_args va) -> sol::table;

[zach2good]

I would add a big fat note here, saying something to the tune of: "APART FROM THIS ONE EXCEPTION, ALL TARGET AND PATH FINDING SHOULD BE DONE EXCLUSIVELY IN CORE"

[zach2good]

and say that this is used for Ixion, and possibly there's another usage for this in assault? I don't remember

[MowFord]

Can do

[zach2good]

And another sub-note: If you have to do expensive operations that are meant for core in Lua, you should be doing them as infrequently as possible: In a mobskill that locks itself off, or anything that isn't on-tick, etc.

[MowFord]

Updated the description

[zach2good]

For any passers-by: This is logic added using TargetFind. Future optimisations using octrees/spatial hashing will happen INSIDE TargetFind.