Weighted Samples

[lvoegtle]

Allow that samples themselves specify a weight to be used for sampling these.

A possible implementation could be:

• Fill a buffer with buffer_size samples
• From that buffer, pick one sample based on sampling weight, and yield that sample
• Discard one random sample from the buffer based on inverse weight
• Add two new samples to the buffer
  But this has the downside, that half of the samples is discarded although being loaded. Research for better algorithms.

The sample weight shall be configured in the task encoder.