Change "--kernel-name" parameter for #!connect command for kql + sql to "--database-name"

[claudiaregio]

To have a clear delineation between kernel and database, let's change the "--kernel-name" parameter for KQL and SQL to "--database-name"

We can leave support for the old syntax and recommend in the output that people update their code to --database-name when using KQL/SQL

[jonsequitur]

This option isn't specifying the database name, it's giving a name to the dynamically-connected kernel.