Simplify `Configuration`

[janbuchar]

• a library may exist to make working with environment-based configuration easier (similar to pydantic-settings in Python)
• we should reconsider the current configuration priority where environment variables take precedence over arguments to the Configuration constructor
• we should consider removing support for the crawlee.json configuration file
• we should move strictly Apify-specific configuration options to the SDK (e.g., ACTOR_DEFAULT_DATASET_ID)

[B4nan]

a library may exist to make working with environment-based configuration easier (similar to pydantic-settings in Python)
we should reconsider the current configuration priority where environment variables take precedence over arguments to the Configuration constructor

To be decided later.

we should consider removing support for the crawlee.json configuration file

Let's confirm with our users (mainly but not only delivery) if they use this, likely nope so fine to remove.

we should move strictly Apify-specific configuration options to the SDK (e.g., ACTOR_DEFAULT_DATASET_ID)

Most important bit, python version already works this way.