Expose isEqual options to the user

[hasparus]

See https://github.com/dethcrypto/earl/pull/165#discussion_r784140229.

Currently, the options documented in https://earljs.dev/docs/advanced/equality-algorithm#algorithm are not exposed to the user. While I personally wouldn't set uniqueNaNs or minusZero to true, some advanced Earl users might need it, especially when migrating from other assertion libraries.