[iOS] Move rejectPromiseWithMessage to RNMLKit core

[coolsoftwaretyler]

modules/react-native-mlkit-face-detection/ios/RNMLKitFaceDetectionModule.swift has this helper function:

// Function to reject a promise with a specified message and domain
func rejectPromiseWithMessage(promise: Promise, message: String, domain: String) {
    promise.reject(
        NSError(domain: domain, code: 1, userInfo: [NSLocalizedDescriptionKey: message])
    )
}

Which I have need for in Barcode Scanning. We should package that up with core, IMO.