Optimize map { ... }.compact calls (#15513)

* Optimize map { ... }.compact

using Enumerable#filter_map, supported since Ruby 2.7

* Add poyfill for Enumerable#filter_map

app/controllers/api/v1/crypto/keys/queries_controller.rb

@@ -17,7 +17,7 @@ class Api::V1::Crypto::Keys::QueriesController < Api::BaseController
   end
 
   def set_query_results
-    @query_results = @accounts.map { |account| ::Keys::QueryService.new.call(account) }.compact
+    @query_results = @accounts.filter_map { |account| ::Keys::QueryService.new.call(account) }
   end
 
   def account_ids