`cacheIdentifier` option as a function?

## **BEFORE YOU SUBMIT** please read the following:
**I'm submitting a feature request**

**Webpack Version:**
5.x

**Babel Core Version**:
7.18.x

**Babel Loader Version**:
8.2.x

**Please tell us about your environment:**
OSX 13.x

**Current behavior:**
`cacheIdentifier` is an option that defaults to stringified json with `@babel/core` version, `babel-loader` version, and "`options`" object.

https://github.com/babel/babel-loader/blob/v8.2.5/src/index.js#L189-L193

**Expected/desired behavior:**
Want to be able to set it to a function whose argument includes values used in the default value.
```
// webpack.config.js

{
loader: 'babel-loader',
options: {
cacheIdentifier({ options, babelCoreVersion, babelLoaderVersion }) {
// returns string
return JSON.stringify({ options, babelCoreVersion, babelLoaderVersion, someOtherKey: 'cache-busting value' });
},
},
},
```

Maybe something like this could work.
```
// babel-loader/src/index.js

const cacheIdentifierOptions = {
options,
"@babel/core": transform.version,
"@babel/loader": version,
};

let {
// ...
cacheIdentifier = JSON.stringify(cacheIdentifierOptions),
// ...
} = loaderOptions;

if (cacheIdentifier === 'function') {
cacheIdentifier = cacheIdentifier(cacheIdentifierOptions);
}
```

* **If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem along with a gist/jsbin of your webpack configuration.**

* **What is the expected behavior?**

* **What is the motivation / use case for changing the behavior?**
The default value makes sense for most use cases and includes info that depends on the file being transpiled, such as filename, but I can't access it :/

Start in src/index.js around lines 189-193, where the default cacheIdentifier is assembled from the Babel and loader versions and options. Confirm how loader options are read, then make the requested behavior complete when cacheIdentifier is a function receiving those default-value inputs while retaining the existing default behavior.

Written by the indexing model from the issue text.