Automatic Precompile Fallback Mechanism

[nlordell]

This issue captures the work to introduce an automatic precompile fallback mechanism to the WebAuthn signing scheme. In particular, given that the RIP-7212 precompile for

This mechanism can be directly built into the WebAuthn signature verification contract, by having the verifier address be a packed uint16(precompileAddress) || fallbackVerifierAddress, this way passkeys can be deployed for chains that don't yet have RIP-7212 implemented but automatically upgrade to them once the precompile becomes available, without having to rotate passkeys.

[nlordell]

Requires 4337 validation.

[nlordell]

4337 team confirmed that they agree to add the required exception to make passkey fallback work.