fix: Agent typing indicator for website widget (#4495)

When we migrated the pubsub tokens from contact to contact inboxes, we missed out on doing this update for the typing indicator events. Hence the agent typing events weren't visible on the widget side. This change fixes that and removes the necessary column contact pubsub token from the model.

fixes: #4476

db/migrate/20220418094715_remove_contact_pubsub_token.rb

@@ -0,0 +1,5 @@
+class RemoveContactPubsubToken < ActiveRecord::Migration[6.1]
+  def change
+    remove_column :contacts, :pubsub_token, :string
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2022_04_09_044943) do
+ActiveRecord::Schema.define(version: 2022_04_18_094715) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"
@@ -325,7 +325,6 @@ ActiveRecord::Schema.define(version: 2022_04_09_044943) do
     t.integer "account_id", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.string "pubsub_token"
     t.jsonb "additional_attributes", default: {}
     t.string "identifier"
     t.jsonb "custom_attributes", default: {}
@@ -334,7 +333,6 @@ ActiveRecord::Schema.define(version: 2022_04_09_044943) do
     t.index ["email", "account_id"], name: "uniq_email_per_account_contact", unique: true
     t.index ["identifier", "account_id"], name: "uniq_identifier_per_account_contact", unique: true
     t.index ["phone_number", "account_id"], name: "index_contacts_on_phone_number_and_account_id"
-    t.index ["pubsub_token"], name: "index_contacts_on_pubsub_token", unique: true
   end
 
   create_table "conversations", id: :serial, force: :cascade do |t|