Feature: Add alias for loading resource

[HypnosNova]

resourceManager.getFromCache is very difficult to use. For example

await engine.resourceManager.load([{
    url: "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.jpg",
}]);

xxxMaterial.texture = engine.resourceManager.getFromCache("xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.jpg");

Sometimes a resource url is a hash string and we don't know what is it util we check the resource by url. We can't know what is it when writing code. And another much worse situation is loading a spine, it has 3 urls and we must join the url array. The code would be very ugly.

If we give LoadItem a name, we can just get cache by their name, for example:

await engine.resourceManager.load([{
    urls: [
        "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.jpg",
        "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.atlas",
        "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.json",
    ],
    type: "spine",
    name: "boy"
}]);


const spine1 = engine.resourceManager.getFromCache('boy'); // it would be very easy to know what we get
// and the up code is the same as
const spine2 = engine.resourceManager.getFromCache([
    "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.jpg",
    "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.atlas",
    "xxx.com/83b812c361e2c2d0bd68626b2b07a58a20fc0839.json",
].join(','));

spine1 === spine2; // true

[codecov]

Codecov Report

Patch coverage: 58.82% and project coverage change: +0.01% 🎉

Comparison is base (b499f94) 65.10% compared to head (2502283) 65.11%.
Report is 7 commits behind head on main.

❗ Current head 2502283 differs from pull request most recent head f4fd985. Consider uploading reports for the commit f4fd985 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1786      +/-   ##
==========================================
+ Coverage   65.10%   65.11%   +0.01%     
==========================================
  Files         473      473              
  Lines       23641    23654      +13     
  Branches     3362     3366       +4     
==========================================
+ Hits        15392    15403      +11     
  Misses       7045     7045              
- Partials     1204     1206       +2     

Files Changed	Coverage Δ
packages/core/src/particle/ParticleGenerator.ts	4.53% <ø> (ø)
...re/src/particle/modules/ParticleGeneratorModule.ts	25.00% <ø> (ø)
packages/core/src/asset/ResourceManager.ts	57.07% <40.90%> (-3.02%)	⬇️
packages/core/src/Background.ts	77.63% <88.88%> (+25.00%)	⬆️
packages/core/src/input/pointer/PointerManager.ts	92.34% <100.00%> (ø)
packages/loader/src/ProjectLoader.ts	30.00% <100.00%> (ø)

... and 3 files with indirect coverage changes

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