Rewrite import feature (#21054)

db/migrate/20230330140036_create_bulk_import_rows.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+class CreateBulkImportRows < ActiveRecord::Migration[6.1]
+  def change
+    create_table :bulk_import_rows do |t|
+      t.references :bulk_import, null: false, foreign_key: { on_delete: :cascade }
+      t.jsonb :data
+
+      t.timestamps
+    end
+  end
+end