Minimize public interface of Crawlee components

[janbuchar]

• Crawlee currently exposes a big part of its internals
• This makes refactoring without breaking changes difficult
• We should make as many things as possible private (protected doesn't help - we still need to maintain BC for subclasses)

[monolithed]

It would be helpful to have a table with aliases and usage examples for properties analogous to external APIs like exposeBinding, exposeFunction, evaluateOnNewDocument, etc. Sometimes standard properties are unavailable, and it’s not always clear how to work around the wrapper’s limitations. For example, injectFile can bypass CORS restrictions, but it would be great if it could also inject scripts into iframes.

[janbuchar]

@monolithed I don't think this is very relevant to the issue described here. Can you elaborate in a separate issue, please?