Example: Add a RIP-7212 compliant WebAuthN validator sample

[kopy-kat]

thanks for adding this! Would you be able to write a test for the validator as well?

[kopy-kat]

closing this as our modules have been moved out of the modulekit and into https://github.com/rhinestonewtf/core-modules/ and https://github.com/rhinestonewtf/experimental-modules/