docs: extract batch processing snippets

[fuguiKz]

Issue number: #1005, #1006

Summary

Changes

• Extracted the inline C# examples from docs/utilities/batch-processing.md into snippet files under examples/BatchProcessing/snippets/ and replaced the Markdown code fences with pymdownx.snippets includes.
• Extracted the inline C# examples from docs/utilities/idempotency.md into snippet files under examples/Idempotency/snippets/ and replaced the Markdown code fences with pymdownx.snippets includes.
• Enabled pymdownx.snippets.dedent_subsections in mkdocs.yml to preserve formatting when including indented subsections (e.g., within tabs/admonitions).

User experience

No intended visual changes to the rendered documentation; this is a maintainability improvement to avoid duplicated/inline code blocks.

Checklist

• I have performed a self-review of this change
• Changes have been tested (make build-docs-website)
• Changes are documented

Fixes #1005
Fixes #1006

[boring-cyborg]

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[hjgraca]

Hi @fuguiKz thanks for opening the pull request and working on this. Due to the current holiday period we might take more time to review your pull request. Thank you once again

[sonarqubecloud]

Quality Gate passed

Issues
26 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
2.6% Duplication on New Code

See analysis details on SonarQube Cloud

[fuguiKz]

Pushed a follow-up commit adding named namespaces to the new snippet files (Sonar rule S3903: types in global namespace). This should bring the SonarCloud Quality Gate back to green once checks rerun.

[fuguiKz]

Update: SonarCloud checks are now green on the latest commit (SonarCloud Code Analysis is passing). Thanks!

[fuguiKz]

FYI the GitHub Actions check suite is in an "action required" state (fork workflow approval), so Actions jobs haven't run yet. Other checks (SonarCloud, etc.) are green.

Could a maintainer approve and run the GitHub Actions workflows for this PR? That should unblock mergeability.