[oden] IO: Load Strings

It's useful. The stock JS way is bad.

oden-js/src/lib.rs

@@ -77,6 +77,12 @@ impl From<std::io::Error> for Error {
     }
 }
 
+impl From<std::str::Utf8Error> for Error {
+    fn from(e: std::str::Utf8Error) -> Self {
+        Error::ConversionError(e.to_string())
+    }
+}
+
 pub type Result<T> = core::result::Result<T, Error>;
 pub type ValueResult = core::result::Result<Value, Error>;