fix: accept arbitrary JSON userData in ApifyRequestList

[vdusek]

Description

• _RequestDetails.user_data was typed dict[str, str], but the platform requestListSources input allows arbitrary JSON values in userData, so e.g. {"depth": 1} raised a ValidationError. Retyped to dict[str, JsonSerializable] (the same alias crawlee's Request.from_url declares).
• Fixed a related pre-existing crash: crawlee's Request.from_url mutates a non-empty user_data dict passed to it (writes __crawlee back into it), and _process_remote_url reused one dict for every URL extracted from a requestsFromUrl source. Any such source with non-empty userData and 2+ extracted URLs crashed with a TypeError on the second request. Each call now gets its own copy of the dict.
• Added regression tests for both cases.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.88%. Comparing base (2cc5602) to head (1800d5d).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #966      +/-   ##
==========================================
- Coverage   89.91%   89.88%   -0.04%     
==========================================
  Files          49       49              
  Lines        3085     3085              
==========================================
- Hits         2774     2773       -1     
- Misses        311      312       +1     

Flag	Coverage Δ
e2e	?
integration	56.95% <0.00%> (-0.04%)	⬇️
unit	78.70% <100.00%> (ø)

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