feat/isomorphic

[MasterKale]

This PR refactors SimpleWebAuthn to work in more runtimes than just Node. This is generally achieved by refactoring away references to Node-specific data classes, like Buffer, and referencing Web APIs in a way that should support use of @simplewebauthn/server in more non-Node runtimes than before.

Non-isomorphic third-party dependencies have also been replaced, with efforts taken to prevent breaking changes to external API inputs and outputs.

Noteworthy changes:

• The project now targets Node 16 and above
• Existing projects that pass in Buffer for method arguments that are now marked Uint8Array should not break, due to Node's Buffer being a subclass of Uint8Array

Registration

• The following values returned from verifyRegistrationResponse() are now a Uint8Array instead of a Buffer
  • aaguid
  • authData
  • clientDataHash
  • credentialID
  • credentialPublicKey
  • rpIdHash

Authentication

• The following values returned from verifyAuthenticationResponse() are now a Uint8Array instead of a Buffer
  • credentialID

Helpers (@simplewebauthn/server/helpers)

• There are several new helpers for working with WebAuthn-related data types that should work in all runtimes:
  • isoCBOR for working with CBOR-encoded values
  • isoCrypto for leveraging the WebCrypto API when working with various WebAuthn/FIDO2 data structures
  • isoBase64URL for encoding and decoding values into base64url (with optional base64 support)
  • isoUint8Array for working with Uint8Arrays
  • cose for working with COSE-related methods and types
• The isBase64URLString() helper is now isoBase64URL.isBase64url()
• The decodeCborFirst() helper is now isoCBOR.decodeFirst()
• The convertPublicKeyToPEM() helper has been removed