Implement Algorithm M

[ellie-idb]

WIP -- do not merge

Depends on changes introduced in #387.

[ellie-idb]

Hey @9il, I'm almost done with this, but I'm getting stuck on how to handle underflowing here. Currently we just assert -- I'm not able to find much literature on how to handle what to do, as a test case like this fails:

auto view = DecimalView!ulong(false, 0, BigUIntView!ulong.fromHexString("88BF4748507FB9900ADB624CCFF8D78897DC900FB0460327D4D86D327219"));
auto coeff = (cast(BigUIntView!uint)view.coefficient).lightConst;
assert (algoM!float(0.0, coeff, cast(int)view.exponent) == float.infinity);
assert (algoM!double(0.0, coeff, cast(int)view.exponent) == 0x1.117e8e90a0ff7p+239);