Updating Search Detector API to reject all queries other than BoolQuery

[saratvemulapalli]

*Issue #195 *

Description of changes:
As count and match detectors is moved to Search Detector Info API, Search Detector API will now filter all queries with backend role filter if enabled.

Also will be making changes to Alerting plugin, where we query Detectors during create Monitor workflow.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Merging #288 into master will not change coverage.
The diff coverage is 75.00%.

@@            Coverage Diff            @@
##             master     #288   +/-   ##
=========================================
  Coverage     71.39%   71.39%           
  Complexity     1871     1871           
=========================================
  Files           195      195           
  Lines          9020     9020           
  Branches        764      764           
=========================================
  Hits           6440     6440           
  Misses         2215     2215           
  Partials        365      365           

Flag	Coverage Δ	Complexity Δ
#cli	79.27% <ø> (ø)	0.00 <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ	Complexity Δ
...est/handler/IndexAnomalyDetectorActionHandler.java	48.77% <ø> (ø)	32.00 <0.00> (ø)
...ransport/SearchAnomalyDetectorTransportAction.java	35.71% <0.00%> (ø)	4.00 <0.00> (ø)
...rch/ad/transport/IndexAnomalyDetectorResponse.java	75.00% <85.71%> (ø)	4.00 <1.00> (ø)

[ohltyler]

LGTM, confirmed in AD plugin this shouldn't break any existing queries as well.

[yizheliu-amazon]

I will merge this PR on behalf of Sarat since he is out today, and it has 2 approvals now.

[saratvemulapalli]

Thanks guys!