Handle special characters better

[curtisy1]

Currently, only a few characters are escaped and sanitized. This is because they appeared in the sample I was testing with at work. However, there's probably a bunch of other evil characters out there the generator should handle (how about ?, !, comma, ', ", <,>) to name just a few

• Check how the official resx ResourceGenerator does escape these. Get at least feature parity (no code stealing)
• Every breaking character gets replaced with a _. The ResourceManager should be able to find both variants (e.g. for JS parsing)
• How do we deal with exotic characters or emojis? Are these even supported in resx? I know Csharp does not support them, so experiment and provide as much support as possible