chore: Enhance contact merge action for identified users (#4886)

- Discard conflicting keys 
- Do not merge if there is already an identified contact

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/controllers/api/v1/widget/base_controller.rb

@@ -44,38 +44,6 @@ class Api::V1::Widget::BaseController < ApplicationController
     }
   end
 
-  def update_contact(email)
-    contact_with_email = @current_account.contacts.find_by(email: email)
-    if contact_with_email
-      @contact = ::ContactMergeAction.new(
-        account: @current_account,
-        base_contact: contact_with_email,
-        mergee_contact: @contact
-      ).perform
-    else
-      @contact.update!(email: email)
-      update_contact_name
-    end
-  end
-
-  def update_contact_phone_number(phone_number)
-    contact_with_phone_number = @current_account.contacts.find_by(phone_number: phone_number)
-    if contact_with_phone_number
-      @contact = ::ContactMergeAction.new(
-        account: @current_account,
-        base_contact: contact_with_phone_number,
-        mergee_contact: @contact
-      ).perform
-    else
-      @contact.update!(phone_number: phone_number)
-      update_contact_name
-    end
-  end
-
-  def update_contact_name
-    @contact.update!(name: contact_name) if contact_name.present?
-  end
-
   def contact_email
     permitted_params.dig(:contact, :email)&.downcase
   end