Reduce memory load

[qgustavor]

Possible changes:

• Use WORKERFS so files can be read without copying the entire data into memory.
• Decompress files on demand. Maybe something like this:

// Archive opening (aka RAROpenArchiveEx)
const archive = await libunrar.openFile(blob_or_file)
// archive.entries is a array of files (or something similar)

// File decompressing
const data = await archive.entries[0].read()

[tnikolai2]

I add WORKERFS version. But it 10x times slower for archive with many small files.