Refactor API structure: update internal handling, enhance input retrieval, and improve template loading

api/entrys/add.php

@@ -2,21 +2,15 @@
 // Set internal to false so that the answer goes to the client
 if (!isset($internal)) {
     $internal = false;
+    define("API_DIR", "../");
 }
 
 // Load Main Library
-require "../api.php";
+require API_DIR . "api.php";
 
-$api = new gbAPI(false);
+$api = new gbAPI(false, $internal);
 
-if ($_SERVER["REQUEST_METHOD"] !== "POST") {
-    $api->answer(400, [
-        "error" => "false_request_method",
-        "error_text" => "Only POST allowed"
-    ]);
-}
-
-$input = json_decode(file_get_contents("php://input"), true);
+$input = $api->getInput();
 
 if (!isset($input["name"]) || !isset($input["text"])) {
     $api->answer(400, [