feat: auto detect first login (#2722)

* 'hide' default email and password env variables

* first login API endpoint

* run code-generators

* frontend indicators for default username and pw

* remove old env variables from docs

* fix env set variable

* remove password from tests

mealie/app.py

@@ -104,7 +104,6 @@ async def system_startup():
             indent=4,
             exclude={
                 "SECRET",
-                "DEFAULT_PASSWORD",
                 "SFTP_PASSWORD",
                 "SFTP_USERNAME",
                 "DB_URL",  # replace by DB_URL_PUBLIC for logs