Implementation of ByteMatrixQRCode

[Benjlet]

Summary

This PR implements 'ByteMatrixQRCode', which allows a byte matrix representation of the generated QR Code data.

I found this to be a very portable format for writing pixels blocks to other image libraries, where these simply translate to a grid of 1s/0s. Originally I was using the ZXing library to achieve this and had to develop that conversion as a wrapper, so believe this is adding something useful.

Unit tests included and all passing for me - I ran this on .NET 6 in VS2022.

I did not update the main README in this request as this would likely be done after/if this is merged, so it can link to the Wiki.

Cheers - love the library.