Decouple ElasticSearch plugin from Trace Analytics

[dlvenable]

Is your feature request related to a problem? Please describe.

The ElasticSearch sink plugin has a lot of configurations specifically for Trace Analytics. The plugin can be made more generic so that it supports other use cases.

Describe the solution you'd like

The configurations in the ElasticSearch sink plugin should be removed from that plugin. Some options to consider:

• Do this work as part of a prepper plugin which runs before the sink plugin
• Support plugins on the ElasticSearch sink
• Create a new plugin type for some of this setup