Supporting GET queries with disable_stats=true and enable_queue_totals=true

[inikulshin]

https://rawcdn.githack.com/rabbitmq/rabbitmq-server/v3.12.12/deps/rabbitmq_management/priv/www/api/index.html

It is possible to disable the statistics in the GET requests and obtain just the basic information of every object. This reduces considerably the amount of data returned and the memory and resource consumption of each query in the system. For some monitoring and operation purposes, these queries are more appropiate. The query string parameter disable_stats set to true will achieve this.

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Recently I added GetQueuesWithoutStatsAsync method, and also made record hierarchy record Queue : QueueWithoutStats : QueueName.

However, this method uses disable_stats=true&enable_queue_totals=true query. And for disable_stats=true query separate method and separate record is required. And there is no way to insert record QueueWithoutStatsAndTotals to the record hierarchy as there is no multiple inheritance. That means, my design is bad.

I think better solution is to have only record Queue : QueueName, mark all the properties of Queue that can be disabled by query parameters as nullable (maybe even integers), and add optional flags to GetQueuesAsync method:

Task<IReadOnlyList<Queue>> GetQueuesAsync(bool disableStats = false, bool enableQueueTotals = false, CancellationToken cancellationToken = default);

Similarly to Exchange:

Task<IReadOnlyList<Exchange>> GetExchangesAsync(bool disableStats = false, CancellationToken cancellationToken = default);

And so on.

@zidad @Pliner @micdenny FYI.

[inikulshin]

Redesigned in #319