"version" command requires specifying a database URL

With a recent build of graphql-engine:

```
$ graphql-engine version
Fatal Error: Either of --metadata-database-url or --database-url option expected
$ graphql-engine --database-url foo version
Hasura GraphQL Engine: v2.0.5
```

I'd expect to be able to run the version command without specifiying a database URL.

Start by reproducing `graphql-engine version` without `--database-url`, then compare its argument handling with `graphql-engine --database-url foo version`. Trace the version command's validation path and verify that the command prints the engine version without requiring either database URL option.

Written by the indexing model from the issue text.