DEV: Refactor uploads_importer script (#29292)

* DEV: Implement uploads command entrypoint

- Setup Thor UploadsCommand for CLI
- First pass at modularizing various parts of the exising `uploads_import` script

* DEV: First attempt at modularizing missing uploads fixer task

Move missing upload fix to a dedicated uploads task implementation unit

* DEV: First attempt at modularizing missing uploads uploader task

Move uploader to a dedicated uploads task implementation unit

* DEV: First attempt at modularizing missing uploads optimizer task

Move optimizer to a dedicated uploads task implementation unit

* DEV: Various follow up fixes to get optimization working

- Start threads early
- Improve "log" message formatting
- Add missing `copy_to_tempfile` method on "uploader" task

* DEV: Refactor a bit more

Deduplicate and move most of threading premitives to base task as-is

* DEV: Remove redundant condition in uploads db migration

* DEV: More deduplication

Move task retry logic to base class and tidy up other implementation
details carried over from the existing script

migrations/lib/cli/upload_command.rb

@@ -3,9 +3,46 @@
 module Migrations::CLI::UploadCommand
   def self.included(thor)
     thor.class_eval do
-      desc "upload", "Upload a file"
+      desc "upload", "Upload media uploads"
+      option :settings,
+             type: :string,
+             desc: "Uploads settings file path",
+             default: "./migrations/config/upload.yml",
+             aliases: "-s",
+             banner: "path"
+      option :fix_missing, type: :boolean, desc: "Fix missing uploads"
+      option :optimize, type: :boolean, desc: "Optimize uploads"
       def upload
-        puts "Uploading..."
+        puts "Starting uploads..."
+
+        validate_settings_file!
+        settings = load_settings
+
+        ::Migrations::Uploader::Uploads.perform!(settings)
+
+        puts ""
+      end
+
+      private
+
+      def load_settings
+        settings = ::Migrations::SettingsParser.parse!(options.settings)
+        merge_settings_from_cli_args!(settings)
+
+        settings
+      end
+
+      def merge_settings_from_cli_args!(settings)
+        settings[:fix_missing] = options.fix_missing if options.fix_missing.present?
+        settings[:create_optimized_images] = options.optimize if options.optimize.present?
+      end
+
+      def validate_settings_file!
+        path = options.settings
+
+        if !File.exist?(path)
+          raise ::Migrations::NoSettingsFound, "Settings file not found: #{path}"
+        end
       end
     end
   end