Better filter display and behavior

[joshuali925]

from opendistro-for-elasticsearch/trace-analytics#15:

Right now the filtering is directly based on on the field names in the index. Can this be made user friendly, example durationInNanos is not user friendly. If this can be changed as latency (in ms) and the at the query layer convert to nanos and apply it in filter.

Also, the filter only supports is, in between and not in between, equal to operation can we support less than, greater than instead?

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from opendistro-for-elasticsearch/trace-analytics#16:

I applied a filter by duration, shouldn't the latency variance change based on the filter?

[joshuali925]

This was addressed by opendistro-for-elasticsearch/trace-analytics#28, the label is now latency which is in milliseconds