refactor: Use ensure_context decorator in Actor class

[vdusek]

Summary

• Replace manual _raise_if_not_initialized() calls with the @ensure_context decorator from Crawlee, matching the pattern already used in ChargingManager
• Add active attribute to _ActorType (replaces _is_initialized) for compatibility with ensure_context
• Remove the now-unused _raise_if_not_initialized method

Reopens #400

Test plan

• CI passes

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 98.27586% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 85.87%. Comparing base (69b8af9) to head (5d633d0).
⚠️ Report is 4 commits behind head on master.

Files with missing lines	Patch %	Lines
src/apify/_utils.py	94.73%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #822      +/-   ##
==========================================
- Coverage   85.92%   85.87%   -0.06%     
==========================================
  Files          46       46              
  Lines        2778     2796      +18     
==========================================
+ Hits         2387     2401      +14     
- Misses        391      395       +4     

Flag	Coverage Δ
e2e	38.05% <81.03%> (+0.97%)	⬆️
integration	59.40% <91.37%> (+0.76%)	⬆️
unit	73.46% <98.27%> (+0.02%)	⬆️

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[Pijukatel]

The tiny small comment is that we now have one more public .active , which is not really needed. In a gigantic class like Actor, that further increases the clutter.

What about making the @ensure_context decorator with a parameter?

Then we can do something like this

_ensure_context = ensure_context("_active")

class Actor:
    ...
    @_ensure_context
    async def open_dataset

[vdusek]

The tiny small comment is that we now have one more public .active , which is not really needed. In a gigantic class like Actor, that further increases the clutter.

What about making the @ensure_context decorator with a parameter?

Sure, good idea. I've implemented a new version of ensure_context that accepts an argument for the SDK.

I implemented it in the SDK rather than changing the one in the Crawlee; this way, we don't have to restrict the lower bound version of Crawlee.

We can unify it again in the next major version of Crawlee & SDK (to have only 1 version of ensure context).