The "imbaud python library" (imp lib), or just imp for short!

TODO:
- define a getPrime function like PyCryptodome's
- rewrite nim-lang/bigints to implement features like Karatsuba multiplication, or even Toom-3 multiplication


PyCryptodome defines getPrime as follows:
```py
def getPrime(N, randfunc=None):
    """Return a random N-bit prime number.

    N must be an integer larger than 1.
    If randfunc is omitted, then :meth:`Random.get_random_bytes` is used.
    """
    if randfunc is None:
        randfunc = Random.get_random_bytes

    if N < 2:
        raise ValueError("N must be larger than 1")

    while True:
        number = getRandomNBitInteger(N, randfunc) | 1
        if isPrime(number, randfunc=randfunc):
            break
    return number
```
in essence infinite random generation until a prime is found