Add action to DELETE /_alerting/destinations/{id}

[skkosuri-amzn]

Issue #, if available:
#232

Description of changes:
Refer: #232

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #233 into master will increase coverage by 0.10%.
The diff coverage is 86.66%.

@@             Coverage Diff              @@
##             master     #233      +/-   ##
============================================
+ Coverage     76.14%   76.24%   +0.10%     
- Complexity      157      162       +5     
============================================
  Files            63       66       +3     
  Lines          2586     2635      +49     
  Branches        402      420      +18     
============================================
+ Hits           1969     2009      +40     
+ Misses          421      412       -9     
- Partials        196      214      +18     

Impacted Files	Coverage Δ	Complexity Δ
...csearch/alerting/action/DeleteDestinationAction.kt	66.66% <66.66%> (ø)	0.00 <0.00> (?)
...ting/transport/TransportDeleteDestinationAction.kt	66.66% <66.66%> (ø)	0.00 <0.00> (?)
...ndistroforelasticsearch/alerting/AlertingPlugin.kt	88.70% <100.00%> (+0.37%)	0.00 <0.00> (ø)
...search/alerting/action/DeleteDestinationRequest.kt	100.00% <100.00%> (ø)	0.00 <0.00> (?)
...lerting/resthandler/RestDeleteDestinationAction.kt	100.00% <100.00%> (ø)	0.00 <0.00> (ø)
...roforelasticsearch/alerting/model/action/Action.kt	70.17% <0.00%> (-10.96%)	0.00% <0.00%> (ø%)
...stroforelasticsearch/alerting/alerts/AlertError.kt	80.00% <0.00%> (-6.67%)	0.00% <0.00%> (ø%)
...relasticsearch/alerting/model/destination/Chime.kt	57.14% <0.00%> (-2.86%)	0.00% <0.00%> (ø%)
...relasticsearch/alerting/model/destination/Slack.kt	57.14% <0.00%> (-2.86%)	0.00% <0.00%> (ø%)
...h/alerting/resthandler/RestExecuteMonitorAction.kt	73.17% <0.00%> (-2.44%)	0.00% <0.00%> (ø%)
... and 22 more

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[qreshi]

NP: I believe the old naming scheme was more appropriate since we typically only begin lowercasing acronyms when they exceed two letters.

This is not a blocker for this PR, we can always change it in another one of the API PRs.