[advancedcontentfilter] Add addon files

- Add hooks
- Add mini-API module powered by Slim
- Add addon settings page powered by VueJS
- Add translation strings
- Add help page

advancedcontentfilter/src/middlewares.php

@@ -0,0 +1,30 @@
+<?php
+
+$container = $slim->getContainer();
+
+// Error handler based off https://stackoverflow.com/a/48135009/757392
+$container['errorHandler'] = function () {
+	return function(Psr\Http\Message\RequestInterface $request, Psr\Http\Message\ResponseInterface $response, Exception $exception)
+    {
+        $responseCode = 500;
+
+		if (is_a($exception, 'Friendica\Network\HTTPException')) {
+			$responseCode = $exception->httpcode;
+		}
+
+		$errors['message'] = $exception->getMessage();
+
+        $errors['responseCode'] = $responseCode;
+
+        return $response
+            ->withStatus($responseCode)
+            ->withJson($errors);
+    };
+};
+
+$container['notFoundHandler'] = function () {
+    return function ()
+	{
+		throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('Method not found'));
+    };
+};