Added Steam inventory management

GDevelop general Feature requests
1

The Steamworks integration is missing inventory management. This could be very useful for creating a skin inventory—like in Counter-Strike—or other systems for the more creative among us (yes, I have an idea in mind).

I’ve thoroughly checked the current integration, but there is no inventory management whatsoever.

It would be great to be able to add this feature!

2

Hey Eragone, I’ve translated your message with Google Translator because the Feature request forum doesn’t compartmentalise features per language.
In the future please consider translating your request to English so other users can read and vote for your request (otherwise only French-speakers will be able to understand).

Thanks!