Fixed unused endpoint key str

[MyGodItsFull0fStars]

When registering API endpoints, the key was not used as the endpoint.
Instead, the model.__tablename__ value was used within the create_handler function and could not be changed by a user of LightAPI.

The problem I see with that approach was that while the example shows that endpoints can be defined using a dictionary:

app.register({"person": Person})
app.register({"custom-name": Company})

In this example, the endpoints person and company are defined with LightAPI as of now. The given endpoint key is ignored further on.

I added some logic that now uses the key, therefore the Company model is now using the endpoint custom-name.
Further on, the / at the beginning of the key string had to be omitted, otherwise the endpoint for Person would be ip-address:8000//person/.

Let me know if you have any questions/suggestions for this commit.

Note: The current implementation requires a Python version >= 3.10 because of https://peps.python.org/pep-0604/. If you envision a larger support with other Python versions, let me know, I can change the code but this will result in less readability.

[iklobato]

Hello @MyGodItsFull0fStars thanks for that! We can absolutely merge it, but can we add some unit tests for this?

[MyGodItsFull0fStars]

Hello @iklobato, oh yeah sure and good catch! I will add some unit tests to it before the merge.