Expose StreamingDirectExchangeBuffer buffer utilization distribution as DataSource metrics

[sopel39]

Similar as for output buffer utilization (#13463), we can track input buffer utilization (after first page is placed in the buffer). This would allow us to identify network bottlenecks

[sopel39]

The idea here is to track io.trino.operator.DirectExchangeBuffer#getRetainedSizeInBytes (distribution over time after first page is received, same as in https://github.com/trinodb/trino/blob/master/core/trino-main/src/main/java/io/trino/execution/buffer/OutputBufferMemoryManager.java#L66). Then such distribution can be exposed via io.trino.exchange.DirectExchangeDataSource#getMetrics.