zed/zed 33 implement adding ingredients to a recipe

[zbigniewzolnierowicz]

• ZED-33 deduplicate test logic
• ZED-33 add definition for ingredient adding
• ZED-33 add update command
• ZED-33 oops forgot about HTTP endpoint for updates
• ZED-33 add tests for updates
• ZED-33 add some tests
• ZED-33 add command and bind it
• ZED-33 add implementation for adding ingredients