chore(curves): memoize EC constants, fix curve tests

[nhtyy]

Added memoization to some curve parameters to avoid string parsing more than once during runtime

The tests in crates/curves also werent working so I enabled the needed feature in dev-deps

[jtguibas]

Did you add this to increase performance of the elliptic curve precompiles?

[nhtyy]

Ya, it doenst look like some of these functions like generator() are used much, but modulus does at least seem to be used from FieldParameters in a few places

Some moduli are parsed as strings (overriding the default of behavior of FieldParameters) rather than as bytes from the const, but I didnt want to change too much

[ctian1]

@nhtyy Could you use lazy_static instead of defining a new macro? Otherwise seems like a good addition, though it's not clear how much effect it really has on performance