Chore: General notification reformatting (#3182)

- I unified where in file the name of `NotificationProvider.name` is placed
- I made sure that all the providers adhere to the signature of `NotificationProvider.send()`
- I made sure that all the providers use `okMsg` if returning success messages directly from the function.
  Here a discussion should be had:
  Should this be refactored into a constant of `NotificationProvider`? I could imagine that `NotificationProvider.SENDING_SUCCESSFULL`  could be a suitable alternative.
- I made sure all providers have the URL they `POST`/`GET` to be extraced into a variable.
  => refactored this way due to Nelsons suggestion

server/notification-providers/smsmanager.js

@@ -2,23 +2,24 @@ const NotificationProvider = require("./notification-provider");
 const axios = require("axios");
 
 class SMSManager extends NotificationProvider {
-
     name = "SMSManager";
 
     /**
      * @inheritdoc
      */
     async send(notification, msg, monitorJSON = null, heartbeatJSON = null) {
+        const okMsg = "Sent Successfully.";
+        const url = "https://http-api.smsmanager.cz/Send";
+
         try {
             let data = {
                 apikey: notification.smsmanagerApiKey,
-                endpoint: "https://http-api.smsmanager.cz/Send",
                 message: msg.replace(/[^\x00-\x7F]/g, ""),
-                to: notification.numbers,
-                messageType: notification.messageType,
+                number: notification.numbers,
+                gateway: notification.messageType,
             };
-            await axios.get(`${data.endpoint}?apikey=${data.apikey}&message=${data.message}&number=${data.to}&gateway=${data.messageType}`);
-            return "SMS sent sucessfully.";
+            await axios.get(`${url}?apikey=${data.apikey}&message=${data.message}&number=${data.number}&gateway=${data.messageType}`);
+            return okMsg;
         } catch (error) {
             this.throwGeneralAxiosError(error);
         }