4.x: Streamable ~ separate streamer cancellation & DisposableContainer

[akarnokd]

The original idea of having StreamerCancellation -> DisposableContainer conflated the two use cases. Former is for Streamer and sub-Streamer management, the latter is a generic resource storage.

Now we have DisposableStreamerCancellation that extends Disposable and thus can be mass cancelled.

reset and clear still not supported because it would allow removing other's disposables and thus causing possible hangs.

[github-actions]

🐷 TruffleHog + Entropy Beauty Scan

Average entropy of changed code: 5.094 bits/char
Verdict: ⚠️ Consider review — entropy outside sweet spot

Changed files entropy:

.github/workflows/gradle_branch.yml: 5.094
.github/workflows/gradle_pr.yml: 4.942
.github/workflows/gradle_preview_jdks.yml: 5.147
.github/workflows/gradle_release.yml: 5.219
.github/workflows/gradle_snapshot.yml: 5.068

✅ No secrets or suspicious high-entropy strings found.

Mid-4 beauty heuristic in action — powered by our entropy chats! 😊

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.67%. Comparing base (c5f1557) to head (82466f2).
⚠️ Report is 1 commits behind head on 4.x.

Additional details and impacted files

@@             Coverage Diff              @@
##                4.x    #8223      +/-   ##
============================================
- Coverage     98.69%   98.67%   -0.02%     
  Complexity     7097     7097              
============================================
  Files           813      813              
  Lines         50017    50017              
  Branches       6764     6764              
============================================
- Hits          49365    49356       -9     
- Misses          450      456       +6     
- Partials        202      205       +3     

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