Add support for printing shoppinglist with thermal printer (#1273)

* Added escpos-php library

* Added button to shoppinglist print menu

* Added to translation

* Added basic printing logic and API call

* Working implementation for printing with the API

* Added openapi json

* Correctly parsing boolean parameter

* Working button in UI

* Change to grocy formatting

* Add Date

* Only show thermal print button when Feature Flag is set

* Fixed API call and added error message parsing

* Undo translation

* Add flag to print quantities as well

* Added printing notes

* Added quantity conversion

* Increse feed

* Fixed that checkbox was undefined, as dialog was already closed

* Added padding

* Formatting

* Added note about user permission

* Fixed error when using notes instead of products

* Review

- Default FEATURE_FLAG_THERMAL_PRINTER to disabled
- Added missing localization strings (and slightly adjusted one)

* Fixed merge conflicts

Co-authored-by: Bernd Bestel <bernd@berrnd.de>

controllers/PrintApiController.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Grocy\Controllers;
+
+use Grocy\Controllers\Users\User;
+use Grocy\Services\StockService;
+
+class PrintApiController extends BaseApiController
+{
+
+	public function PrintShoppingListThermal(\Psr\Http\Message\ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response, array $args) {
+
+		try
+		{
+			User::checkPermission($request, User::PERMISSION_SHOPPINGLIST);
+
+			$params = $request->getQueryParams();
+
+			$listId = 1;
+			if (isset($params['list'])) {
+				$listId = $params['list'];
+			}
+
+			$printHeader = true;
+			if (isset($params['printHeader'])) {
+				$printHeader = ($params['printHeader'] === "true");
+			}
+			$items = $this->getStockService()->GetShoppinglistInPrintableStrings($listId);
+			return $this->ApiResponse($response, $this->getPrintService()->printShoppingList($printHeader, $items));
+		}
+		catch (\Exception $ex)
+		{
+			return $this->GenericErrorResponse($response, $ex->getMessage());
+		}
+	}
+
+	public function __construct(\DI\Container $container)
+	{
+		parent::__construct($container);
+	}
+}