FR: INumber interface implementation (generic math)

[flexxxxer]

INumber<TSelf> interface is available in .net7.0 and will be available in .net8.0. I propose to implement this interface for ByteSize type in order to be able to use ByteSize type in code with generalised maths, which would be very convenient. However, this requires a lot of time and code, so I suggest to implement INumber interface in stages, and I am willing to help with this. the corresponding pull reqests will contain the name of this issue.