feat: Ability to delete account for administrators (#1874)

## Description

Add account delete option in the user account settings.

Fixes #1555 

## Type of change

- [ ] New feature (non-breaking change which adds functionality)


![image](https://user-images.githubusercontent.com/40784971/110349673-edcc5200-8058-11eb-8ded-a31d15aa0759.png)

![image](https://user-images.githubusercontent.com/40784971/110349778-0c324d80-8059-11eb-9291-abfbffedde5e.png)


## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>
Co-authored-by: Sojan Jose <sojan.official@gmail.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

spec/mailers/administrator_notifications/account_notification_mailer_spec.rb

@@ -0,0 +1,116 @@
+require 'rails_helper'
+require Rails.root.join 'spec/mailers/administrator_notifications/shared/smtp_config_shared.rb'
+
+RSpec.describe AdministratorNotifications::AccountNotificationMailer do
+  include_context 'with smtp config'
+
+  let!(:account) { create(:account) }
+  let!(:admin) { create(:user, account: account, role: :administrator) }
+
+  describe 'account_deletion' do
+    let(:reason) { 'manual_deletion' }
+    let(:mail) { described_class.with(account: account).account_deletion(account, reason) }
+    let(:deletion_date) { 7.days.from_now.iso8601 }
+
+    before do
+      account.update!(custom_attributes: {
+                        'marked_for_deletion_at' => deletion_date,
+                        'marked_for_deletion_reason' => reason
+                      })
+    end
+
+    it 'renders the subject' do
+      expect(mail.subject).to eq('Your account has been marked for deletion')
+    end
+
+    it 'renders the receiver email' do
+      expect(mail.to).to eq([admin.email])
+    end
+
+    it 'includes the account name in the email body' do
+      expect(mail.body.encoded).to include(account.name)
+    end
+
+    it 'includes the deletion date in the email body' do
+      expect(mail.body.encoded).to include(deletion_date)
+    end
+
+    it 'includes a link to cancel the deletion' do
+      expect(mail.body.encoded).to include('Cancel Account Deletion')
+    end
+
+    context 'when reason is manual_deletion' do
+      it 'includes the administrator message' do
+        expect(mail.body.encoded).to include('This action was requested by one of the administrators of your account')
+      end
+    end
+
+    context 'when reason is not manual_deletion' do
+      let(:reason) { 'inactivity' }
+
+      it 'includes the reason directly' do
+        expect(mail.body.encoded).to include('Reason for deletion: inactivity')
+      end
+    end
+  end
+
+  describe 'contact_import_complete' do
+    let!(:data_import) { build(:data_import, total_records: 10, processed_records: 8) }
+    let(:mail) { described_class.with(account: account).contact_import_complete(data_import).deliver_now }
+
+    it 'renders the subject' do
+      expect(mail.subject).to eq('Contact Import Completed')
+    end
+
+    it 'renders the processed records' do
+      expect(mail.body.encoded).to include('Number of records imported: 8')
+      expect(mail.body.encoded).to include('Number of records failed: 2')
+    end
+
+    it 'renders the receiver email' do
+      expect(mail.to).to eq([admin.email])
+    end
+  end
+
+  describe 'contact_import_failed' do
+    let(:mail) { described_class.with(account: account).contact_import_failed.deliver_now }
+
+    it 'renders the subject' do
+      expect(mail.subject).to eq('Contact Import Failed')
+    end
+
+    it 'renders the receiver email' do
+      expect(mail.to).to eq([admin.email])
+    end
+  end
+
+  describe 'contact_export_complete' do
+    let!(:file_url) { 'http://test.com/test' }
+    let(:mail) { described_class.with(account: account).contact_export_complete(file_url, admin.email).deliver_now }
+
+    it 'renders the subject' do
+      expect(mail.subject).to eq("Your contact's export file is available to download.")
+    end
+
+    it 'renders the receiver email' do
+      expect(mail.to).to eq([admin.email])
+    end
+  end
+
+  describe 'automation_rule_disabled' do
+    let(:rule) { instance_double(AutomationRule, name: 'Test Rule') }
+    let(:mail) { described_class.with(account: account).automation_rule_disabled(rule).deliver_now }
+
+    it 'renders the subject' do
+      expect(mail.subject).to eq('Automation rule disabled due to validation errors.')
+    end
+
+    it 'renders the receiver email' do
+      expect(mail.to).to eq([admin.email])
+    end
+
+    it 'includes the rule name in the email body' do
+      expect(mail.body.encoded).to include('Test Rule')
+    end
+  end
+end