Add ARM64 support, unify encoding, and upgrade to WiX 5

[Amrsatrio]

Three things in this PR:

1. I've added native ARM64 support so that this is no longer emulated on Snapdragon laptops (which I'm daily driving).
2. I've forced the compiler to interpret the files as UTF-8 encoding.
   I have my development environment set to Japanese locale, and due to no BOM in the source files, the parsing of restart keywords JSON array fails because cl.exe interpreted them as code page 932.
3. Upgraded to WiX 5 because WiX 3 is no longer maintained. I used the HeatWave VS2022 extension to perform the conversion. This is the first time I'm touching WiX so apologies for any mistakes.

Tested:

a. Installation
b. Uninstallation
c. TV test function (turns off + turns on after 5s successfully)

Todo:

• Update CI