`addObserver` cannot take multiple `NSKeyValueObservingOptions`

[dickermoshe]

Observed(player).addObserver(
      observer,
      forKeyPath: "timeControlStatus".toNSString(),
      options:
          NSKeyValueObservingOptions.NSKeyValueObservingOptionInitial | // ERROR: The operator '|' isn't defined for the type 'NSKeyValueObservingOptions'.

          NSKeyValueObservingOptions.NSKeyValueObservingOptionNew,
      context: nullptr,
    );

addObserver should take an int instead of an enum.

[dickermoshe]

Related to #1518