Metadata extraction pipeline

[kirillt]

Port it from https://github.com/ARK-Builders/arklib-android

[kirillt]

If we make this pipeline in Rust, we'll not only be able to ensure consistency between platforms, but also render previews and thumbnails on powerful server and allow light devices to just sync them over the network.

See:

• ark-cli: Server mode and cache pre-generation ark-core#47