Use Utils\make_temp_file() / Utils\make_temp_dir() for package ZIP install temp paths - #250

Package_Command::install() still built temporary ZIP and extraction paths manually with get_temp_dir() + uniqid(), despite WP-CLI now providing dedicated temp helpers. This PR migrates those call sites and adds acceptance coverage for remote ZIP flows that exercise both download and extraction error/success paths.

• Temp path helper migration

  • Replaced manual temp ZIP filename generation with Utils\make_temp_file( 'wp-cli-package_', '.zip' ).
  • Replaced manual temp extraction directory path generation with Utils\make_temp_dir( 'wp-cli-package_' ).
  • Keeps existing install flow intact while relying on core temp-path semantics (pre-created temp dir, normalized path handling).

• Remote ZIP acceptance coverage

  • Added scenario for successful remote ZIP install via locally served ZIP fixture.
  • Added scenario for successful install from alternate ZIP layout (files at archive root).
  • Added failure scenarios for invalid ZIP contents and HTTP 404 download response.

• Illustrative change

// Before
$temp = Utils\get_temp_dir() . uniqid( 'wp-cli-package_', true ) . '.zip';
$dir_package = Utils\get_temp_dir() . uniqid( 'wp-cli-package_', true );

// After
$temp = Utils\make_temp_file( 'wp-cli-package_', '.zip' );
$dir_package = Utils\make_temp_dir( 'wp-cli-package_' );

• Fixes Use Utils\make_temp_file() and Utils\make_temp_dir() for temporary paths #249