Move events index datatable row to a partial

- clean up columns
- tag unregistered submitters & speakers
- implement caching

app/models/difficulty_level.rb

@@ -1,5 +1,5 @@
 class DifficultyLevel < ApplicationRecord
-  belongs_to :program
+  belongs_to :program, touch: true
   has_many :events, dependent: :nullify
 
   has_paper_trail ignore: [:updated_at], meta: { conference_id: :conference_id }

app/models/event_type.rb

@@ -1,5 +1,5 @@
 class EventType < ApplicationRecord
-  belongs_to :program
+  belongs_to :program, touch: true
   has_many :events, dependent: :restrict_with_error
 
   has_paper_trail meta: { conference_id: :conference_id }

app/models/event_user.rb

@@ -2,6 +2,6 @@ class EventUser < ApplicationRecord
   # TODO: Do we need these roles?
   ROLES = [%w[Speaker speaker], %w[Submitter submitter], %w[Moderator moderator]]
 
-  belongs_to :event
+  belongs_to :event, touch: true
   belongs_to :user
 end

app/models/track.rb

@@ -4,7 +4,7 @@ class Track < ApplicationRecord
 
   resourcify :roles, dependent: :delete_all
 
-  belongs_to :program
+  belongs_to :program, touch: true
   belongs_to :submitter, class_name: 'User'
   belongs_to :room
   belongs_to :selected_schedule, class_name: 'Schedule'

app/models/user.rb

@@ -22,6 +22,8 @@ class User < ApplicationRecord
 
   before_create :setup_role
 
+  after_save :touch_events
+
   # add scope
   scope :comment_notifiable, ->(conference) {joins(:roles).where('roles.name IN (?)', [:organizer, :cfp]).where('roles.resource_type = ? AND roles.resource_id = ?', 'Conference', conference.id)}
 
@@ -231,6 +233,10 @@ class User < ApplicationRecord
     end
   end
 
+  def touch_events
+    event_users.each(&:touch)
+  end
+
   ##
   # Check if biography has an allowed number of words. Used as validation.
   #