InjectModel decorator for multiple databases is broken since version 9.1.0 about mongoose

[jmcdo29]

In my opinion, it shouldn't remain optional if you have multiple databases. If you have Connection1 and Connection2 and you are @InjectModel(SomeModel1.name) and SomeModel1 is in both connections, are you injecting it for Connection1 or Connection2? By adding the connection name, you are making the explicit, conscious choice on which connection you are using, and leading to less guesswork by other devs, and by the framework. If you want to not need to pass a connection name by default, and use one of the X connections, leave the default connection without a name, and the framework will properly use the connection name default. This is how it has been working in both @nestjs/sequelize and @nestjs/typeorm and has pretty much been accepted as the right way to go about multiple connections