Improve Base64 encode/decode performance

[samsharp99]

For large packet sizes (>1Mb), the Base64 encode/decode functions are not performant.

Investigate and see if improvements can be made to increase library performance.

[francois-normandin]

I'd love some feedback on this library, performance-wise.
https://github.com/LabVIEW-Open-Source/Serializer.Base64

I know it is 15% faster than the one found on NI forums for short strings (such as PEM certificates), but I have not tested it for large payloads. I assume a sort of in-place algorithm is what you're looking for... I'm interested in working on this.
Let me know.

[francois-normandin]

ok, this one is really a gem: https://forums.ni.com/t5/Example-Code/Fast-Base64-Encoder-Decoder-using-LabVIEW
It is MIT license, so I'll include in the one I mentioned above.

By the way, this is the kind of improvement you're looking at for a 800kB payload:

(I toggled between my take on Base64 and this VI)

It does not check for validity of the string though, such as removing all whitespaces (space, tabs, CR, LF, etc.)