PersonCard: get top_identifiers from term instead

This is now directly available from the LegislativePeriod object (called
'term') so there's no need to pass it to the initializer.

lib/page/term_table.rb

@@ -89,7 +89,6 @@ def people
         PersonCard.new(
           person:          person,
           term:            term,
-          top_identifiers: top_identifiers
         )
       end
     end

lib/person_cards.rb

@@ -1,13 +1,11 @@
 # frozen_string_literal: true
 
 class PersonCard
-
-  # TODO: pass fewer arguments!
-  def initialize(person:, term:, top_identifiers:)
+  def initialize(person:, term:)
     @person          = person
     @term            = term
     @legislature     = term.legislature
-    @top_identifiers = top_identifiers # get from Legislature
+    @top_identifiers = term.top_identifiers
   end
 
   def proxy_image