Optimizations and clean up

[widberg]

Avoid recompressing resource bodies when writing to the pool

Parallelize reading/writing the actual BigFile file by only scanning for resource offsets the first time through and not actually reading/decompressing anything

Store binary versions of resources in a hidden folder and use those to avoid redoing work when importing if none of the exported files were modified.

Use arrayfire or similar for reverse crc

Use rayon for sorting and filtering in the GUI, and potentially other places

Use base64 for large byte arrays when serializing (https://docs.rs/serde_with/latest/serde_with/base64/index.html ?).