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/onebot.js

@@ -2,23 +2,23 @@ const NotificationProvider = require("./notification-provider");
 const axios = require("axios");
 
 class OneBot extends NotificationProvider {
-
     name = "OneBot";
 
     /**
      * @inheritdoc
      */
     async send(notification, msg, monitorJSON = null, heartbeatJSON = null) {
-        let okMsg = "Sent Successfully.";
+        const okMsg = "Sent Successfully.";
+
         try {
-            let httpAddr = notification.httpAddr;
-            if (!httpAddr.startsWith("http")) {
-                httpAddr = "http://" + httpAddr;
+            let url = notification.httpAddr;
+            if (!url.startsWith("http")) {
+                url = "http://" + url;
             }
-            if (!httpAddr.endsWith("/")) {
-                httpAddr += "/";
+            if (!url.endsWith("/")) {
+                url += "/";
             }
-            let onebotAPIUrl = httpAddr + "send_msg";
+            url += "send_msg";
             let config = {
                 headers: {
                     "Content-Type": "application/json",
@@ -37,7 +37,7 @@ class OneBot extends NotificationProvider {
                 data["message_type"] = "private";
                 data["user_id"] = notification.recieverId;
             }
-            await axios.post(onebotAPIUrl, data, config);
+            await axios.post(url, data, config);
             return okMsg;
         } catch (error) {
             this.throwGeneralAxiosError(error);