Fix: Linter warnings (#137)

* Automaticly fixable eslint issues, mostly 3 -> 2 space indentation

* fix: updated plex_userid to camelcase

* Linted and some consistency refactor on middleware

* eslint uses ecmaversion 2020 & allow empty catch rule

* Started linting source files

* Fixed eslint errors & improved a lot of error handling

* Set 2 eslint rules as warning temporarly

src/media_classes/player.js

@@ -1,12 +1,12 @@
 class Player {
-   constructor(device, address) {
-      this.device = device;
-      this.ip = address;
-      this.platform = undefined;
-      this.product = undefined;
-      this.title = undefined;
-      this.state = undefined;
-   }
+  constructor(device, address) {
+    this.device = device;
+    this.ip = address;
+    this.platform = undefined;
+    this.product = undefined;
+    this.title = undefined;
+    this.state = undefined;
+  }
 }
 
 module.exports = Player;