Add ability to block words in usernames (#35407)

app/models/form/username_block_batch.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class Form::UsernameBlockBatch < Form::BaseBatch
+  attr_accessor :username_block_ids
+
+  def save
+    case action
+    when 'delete'
+      delete!
+    end
+  end
+
+  private
+
+  def username_blocks
+    @username_blocks ||= UsernameBlock.where(id: username_block_ids)
+  end
+
+  def delete!
+    verify_authorization(:destroy?)
+
+    username_blocks.each do |username_block|
+      username_block.destroy
+      log_action :destroy, username_block
+    end
+  end
+
+  def verify_authorization(permission)
+    username_blocks.each { |username_block| authorize(username_block, permission) }
+  end
+end