v2 cleanup (#427)

* refactor: remove useless template

* refactor: handle promise

* refactor: associate labels to fields

* refactor: simplify checking if element exists

* refactor: prevent reassigning

* refactor: avoid wildcard imports

* refactor: simplify imports

* refactor: simplify boolean comparison

* chore: version bump

apps/server/package.json

@@ -2,7 +2,7 @@
   "name": "ontime-server",
   "type": "module",
   "main": "src/index.ts",
-  "version": "2.0.0-beta6",
+  "version": "2.0.0",
   "exports": "./src/index.js",
   "dependencies": {
     "body-parser": "^1.20.0",