Decouple Database Selection from Data Source

When creating a Data Source, most Connectors currently include the selection of a Database and the Schema Browser shows just the Tables in the chosen Database.

It would be preferable to just set the server cection details and then list all available databases in the Schema Browser.

This also means that when saving the Data Source to the library, if there are multiple databases, only one Data Source needs to be saved instead of many (10, 20, 50), and when the connection details change, these only need to be updated in a single place.

This is mainly a problem when connecting to Cloud databases where many databases are exposed under a single endpoint. However it is not limited to these platforms.