[Feature Request]: Encryption

[lukehmcc]

Currently uploadBlob simply uploads the raw blob of the file to my s5 node. This is, ok, but for many use cases I don't want to have to trust my node. In order to upload, you already have to have an API instance with a seed, so encrypting based on that should be fine afaik (not an expert here).

When encrypting a file, it should also generate a unique decryption key so if I want to send the file in a link, I can include the decryption key alongside the CID so it's fully E2EE.

I know I could implement E2EE myself with public key encryption, but if it's most of the work is already done in the library, I feel like it makes more sense to do it there. Especially considering #3 and how decryption should be handled there.