BO34 - Create a DAL function to update informations about the conference's venue

[gregoriopalama]

Add a DAL function in the Venue API.

The function should accept the informations about the venue:

• name (required);
• langitude (required);
• latitudde (required);
• address (required);
• mapId (optional). If provided, will use it to tell the Maps API to style the map with the corresponding style for the given mapId;
• description (optional);

The response will be an error if something goes wrong. Otherwise, the function will provide the updated venue object.