[DATA-525] Druid Alert

[ShilpaSivanesan]

No description provided.

[ShilpaSivanesan]

@Gauravshah Added support only for timeseries queries
could handle query of
i) with filter(s)
ii) without filters
iii) single aggregation
iv) aggregation types (count, hyperunique, longsum, doublesum)
v)multiple queries in alert conditions

Working on multiple aggregations and other aggregation types

[ShilpaSivanesan]

Added support for
Query Types - timeseries, groupBy , topN
filter types - selector, regex, in
aggregation types - count, hyperunique, longsum, doublesum