Support for field aliases in Kibana

[rayafratkina]

Describe the feature:
In elastic/elasticsearch#23714 (elastic/elasticsearch#32172) Elasticsearch has added support for field aliases. This issue will track the integration of these into Kibana.

Describe a specific use case for the feature:
TBD

Action items:

• Investigate the impact of the initial PR - what will break if aliases are added?

[stratoula]

You can add custom labels now in your fields so I think we can close this issue