Lastresort Web Application, using WASM

[ctsrc]

Similar to the plan for Pgen ctsrc/Pgen#5

I want to make WASM build in the future and a corresponding Single-Page Application website where the tool can run. That way people can test the tool right away without having to install anything.

The Web Application version will be limited to encoding and decoding files of small size. Perhaps something like a 4 MiB limit. This is both because there is a limit anyway on how much data we want to do in the context of a browser, and also because the main intentions for the Web Application is:

• Simple demo before you decide to install it
• Tool is mainly useful for small files anyway at the moment
• In the case where you are encoding data on one device, and decoding it on another, where one of the devices is not connected to the Internet but the other one is, it's convenient to be able to run the tool on one of the devices without having to install anything
• In some cases, perhaps both devices are connected to the Internet, but for whatever reason they cannot communicate directly (for example they are on different subnets, or on entirely different local networks, etc etc) and you don't want to upload to any third party or send the file with P2P either