Add initial pass at queue details support

[rmccue]

See #273.

Adds a new useQueue hook which provides the ability to fetch both the full queue's length and details for each item within it. This builds on the GCKMediaQueue functionality under the hood.

For example, this can be used to show the queued items to the user with something like:

import React, { useEffect, useState } from 'react';
import { FlatList, Text, View } from 'react-native';
import { MediaQueueItem } from '../react-native-google-cast/src';
import MediaQueue from '../react-native-google-cast/src/api/MediaQueue';
import useQueue from '../react-native-google-cast/src/api/useQueue';

interface ItemProps {
	id: number,
	queue: MediaQueue,
}
const QueueItem = ( props: ItemProps ) => {
	const [ item, setItem ] = useState<MediaQueueItem | null>( null );
	useEffect( () => {
		props.queue.getItemById( props.id ).then( item => setItem( item ) );
	}, [ props.id ] );

	return (
		<View>
			<Text>{ item?.mediaInfo.metadata?.title || 'Loading…' }</Text>
		</View>
	)
}

export default function Queue() {
	const queue = useQueue();

	if ( queue === null ) {
		return null;
	}

	return (
		<FlatList
			data={ queue.queuedIds }
			keyExtractor={ id => `${ id }` }
			renderItem={ ( { item } ) => (
				<QueueItem
					id={ item }
					queue={ queue }
				/>
			) }
		/>
	);
}

I have not yet implemented error handling (so the promises can hang forever), nor added full inline documentation, so leaving as draft for now. The JS side of things is also a little janky right now.

[ghost]

DeepCode's analysis on #260046 found:

• ℹ️ 1 minor issue. 👇

Top issues

Description	Example fixes
Missing JSDoc return type. Occurrences: useQueue.ts:4 useQueue.ts:7	🔧 Example fixes

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[rmccue]

@petrbela I'm happy to clean up any final stuff on here and prepare it for merge, but before I do so, can I get a 👍 or 👎 on the approach? I'm using this in my app, and it's been fairly easy to integrate, but happy to consider alternative API designs if you'd prefer.