Sockets Io Uring Write Backpressure And Adaptive Reads

Existing :ref:io_uring <envoy_v3_api_field_extensions.network.socket_interface.v3.DefaultSocketInterface.io_uring_options> deployments now apply write backpressure by default, so a write can return EAGAIN once the write buffer exceeds write_high_watermark_bytes (128 KiB) and resume at or below write_low_watermark_bytes (16 KiB). The readv-based read buffer also grows adaptively up to 16 times read_buffer_size for large transfers.