feat: Asynchronous initialization of Parse Server (#8232)

BREAKING CHANGE: This release introduces the asynchronous initialization of Parse Server to prevent mounting Parse Server before being ready to receive request; it changes how Parse Server is imported, initialized and started; it also removes the callback `serverStartComplete`; see the [Parse Server 6 migration guide](https://github.com/parse-community/parse-server/blob/alpha/6.0.0.md) for more details (#8232)

spec/.eslintrc.json

@@ -34,7 +34,8 @@
       "jequal": true,
       "create": true,
       "arrayContains": true,
-      "databaseAdapter": true
+      "databaseAdapter": true,
+      "databaseURI": true
     },
     "rules": {
       "no-console": [0],