`wasm-unsafe-eval` support

[antonok-edm]

When salvation encounters a Content Security Policy with the wasm-unsafe-eval directive, it reports:

Bad content security policy: Expecting source-expression but found "'wasm-unsafe-eval'".

According to https://caniuse.com/?search=wasm-unsafe-eval, wasm-unsafe-eval is supported by 87.81% of all users globally, which is quite broad and it's probably reasonable to count it as a valid directive now.

[kingthorin]

Ref: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/script-src