Implement felt to bigint functions

[pefontana]

Implement felt to bigint functions

Since various crates have to work with BigInts and BigUints operations, here we implement some Felt to BigInt and Biguint conversions.

• pub fn felt_to_biguint(felt: Felt) -> BigUint
• pub fn felt_to_bigint(felt: Felt) -> BigInt
• pub fn biguint_to_felt(biguint: &BigUint) -> Felt
• pub fn bigint_to_felt(bigint: &BigInt) -> Felt

Does this introduce a breaking change?

No

[Oppen]

Since we now have the types in the same crate, would it make sense to implement the From<Felt> for BigUint and the like?

[0xLucqs]

Maybe something like From<Felt> for BigUint && BigInt and a function implemented on the felt struct to_biguint idk, i don't really like this kind of helper functions, or maybe in a utils crate

[pefontana]

Maybe something like From<Felt> for BigUint && BigInt and a function implemented on the felt struct to_biguint idk, i don't really like this kind of helper functions, or maybe in a utils crate

Sure @LucasLvy !
Done!