Chore: Replace NullChapter with NullChapterable

This will replace `NullChapter` with `NullChapterable`, which will
hopefully simplify things, I don't think we need both or a `NullClub`,
`NullChapterable` should cover everything.

Refs: #5349

app/controllers/ambassador_controller.rb

@@ -43,7 +43,7 @@ def current_ambassador
   end
 
   def current_chapterable
-    @current_chapterable ||= current_ambassador.chapterable || ::NullChapter.new
+    @current_chapterable ||= current_ambassador.chapterable || ::NullChapterable.new
   end
 
   def current_profile

app/controllers/chapter_ambassador_controller.rb

@@ -40,7 +40,7 @@ def current_ambassador
   end
 
   def current_chapter
-    @current_chapter ||= current_ambassador.chapter || ::NullChapter.new
+    @current_chapter ||= current_ambassador.chapter || ::NullChapterable.new
   end
 
   def chapter_ambassador

app/models/account.rb

@@ -1053,11 +1053,11 @@ def assigned_to_chapter?
   end
 
   def current_chapterable
-    current_primary_chapter || current_primary_club || ::NullChapter.new
+    current_primary_chapter || current_primary_club || ::NullChapterable.new
   end
 
   def current_chapter
-    current_primary_chapter || ::NullChapter.new
+    current_primary_chapter || ::NullChapterable.new
   end
 
   def current_primary_chapter

app/null_objects/null_account.rb

@@ -38,7 +38,7 @@ def authenticated?
   end
 
   def current_chapter
-    NullChapter.new
+    NullChapterable.new
   end
 
   class NullCertificates

app/null_objects/null_chapterable.rb

@@ -1,5 +1,21 @@
 class NullChapterable < NullObject
+  def name
+    nil
+  end
+
+  def summary
+    nil
+  end
+
   def primary_contact
     nil
   end
+
+  def chapter_program_information
+    ChapterProgramInformation.none
+  end
+
+  def build_chapter_program_information
+    ChapterProgramInformation.none
+  end
 end

spec/null_objects/null_chapter_spec.rb → spec/null_objects/null_chapterable_spec.rb

@@ -1,7 +1,7 @@
 require "rails_helper"
 
-RSpec.describe NullChapter do
-  let(:null_chapter) { NullChapter.new }
+RSpec.describe NullChapterable do
+  let(:null_chapter) { NullChapterable.new }
 
   describe "#name" do
     it "returns nil" do