[Suggestion] A module that includes BigInt utilities

[roj1512]

BigInt utilities include, but are not limited to:

• A function that takes in x, y, z, and calculates a (x ** y) % z to power, like Python’s built-in pow. Why not just do (x ** y) % z? Because it is really slow for large ints, and there are faster ways.
• A function that converts Uint8Arrays to BigInts (with support for signed BigInts).
• A function that converts BigInts to Uint8Arrays (with support for signed BigInts).
• A function that takes n, and returns a random BigInt that has a maximum byte length of n.
• A function that takes min, max, and returns a random BigInt in that range.
• Alternative to Math.min, Math.max.