[backport] Add Normalize Pipeline Aggregation (#56399)

[talevy]

This aggregation will perform normalizations of metrics
for a given series of data in the form of bucket values.

The aggregations supports the following normalizations

• rescale 0-1
• rescale 0-100
• percentage of sum
• mean normalization
• z-score normalization
• softmax normalization

To specify which normalization is to be used, it can be specified
in the normalize agg's normalizer field.

For example:

{
  "normalize": {
    "buckets_path": <>,
    "normalizer": "percent"
  }
}