Added toDerSignature function used to convert a raw ECDSA signature into DER-encoded format for compatibility with our backend, which requires DER signatures
[BREAKING CHANGE] renamed decryptBundle to decryptCredentialBundle (for decrypting email auth/recovery and oauth credential bundles) in order to distinguish from the new decryptExportBundle (for decrypting bundles containing wallet mnemonics or private key material)
93666ff: turnkey/crypto standard HPKE encryption, first major release. Allows for programmatic importing in environments like node. Moved some encoding helper functions to turnkey/encoding