Update and improve CSP

[damienbod]

Use:

builder.AddScriptSrc()
                    .Self()
                    .WithHash256("ZD0chCyBaNHl+4UwQHJIHGoYhKwMeyCXGgJTKW5/67E=")
                    .WasmUnsafeEval();

[damienbod]

blocking, does not work with Blazor due to the scripts