Simplify Search::PageSearcher#search

Remove #validate_query as it's unnecessary. validate_query checks
that query is not black, so we can make the same inline check.

app/services/search/page_searcher.rb

@@ -7,7 +7,7 @@ def initialize(params)
 
   def search
     [*@queries].each do |search_type, query|
-      if !validate_query(query)
+      if query.blank?
         next
       else
         case search_type.to_s
@@ -35,11 +35,6 @@ def search
 
   private
 
-  def validate_query(query)
-    # if query is an empty array, nil or an empty string, skip filtering for that query
-    [[], nil, ''].include? query ? false : true
-  end
-
   def combine_collections(collection1, collection2)
     # get union of unique values in collection1 and collection2
     arr = (collection1 | collection2).uniq