Messages Cleanup

Added basic cleanup to messages; we currently have the option to either delete messages when we ack them (disabled by default) or to set a limit on the queue size (unlimited by default).

New configuration:

export interface StrataServiceOptions {
    redis : RedisOptions;
    logging ?: LoggerConfig;
    service ?: {
        id ?: string,
        name ?: string;
        concurrency ?: number;

        // This replaces `queuePrefixes`
        queues ?: {
            prefixes ?: {
                request ?: string;
                response ?: string;
            },
            trimWait ?: number;
            maxTrimWait ?: number;
            maxLength ?: number;
            deleteOnAck ?: boolean;
        }
    };
    services ?: {
        [ serviceName : string ] : string;
    };

    // Also support arbitrary keys
    [ key : string ] : unknown;
}