CLI Request: Alter the database schema to allow multiple lecturers on a module

[edwardUL99]

Add a new table to the database to record this.

You will also need to add a vector of lecturers to the Module class. Once you do this and map the list from the database into the Module class correctly on retrieval from the database (and saving/updating), it shouldn't need a new class/DatabaseItem

Requesting CLI issue: edwardUL99/StudSysCppCLI#76