[Feature]: Memory consumption of assets may to reduce in development mode

[h-a-n-a]

What problem does this feature solve?

In development mode, assets are stored twice in Rspack:

• Assets being stored in Compilation.asset on the Rust side
• Assets being emitted to OutputFileSystem on the Node side in memfs

BoxSource is the backing struct of CompilationAsset. It contains non-continuous memory spreading across internal sources.
This is the same as webpack's implementation. Additionally, assets are emitted to memfs as well.

We can might migrate memfs from Node.js to Rust, of course with some tinkering to let assets only being stored once.
On top of rust memfs, again this is just a basic idea, so it might not be as precise, we can use a data structure using path and BoxSource to store code, skipping another buffer copy.

What does the proposed API of configuration look like?

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