`ip_range` aggregation does not automatically generate a `key` for each bucket

[jpountz]

While writing tests for the ip_range aggregation, I noticed that it does not automatically generate a key for each range, while the range aggregation on a numeric field does. Should we make this consistent?

[colings86]

@elastic/es-search-aggs

[nikhilbarar]

Is this issue accepted?

[talevy]

@nikhilbarar the exact details may not have been hashed out, but since this issue was recently tagged with adoptme then yes, it has been accepted as something to look into fixing