GH-47009: [C#] ExportedAllocationOwner should use 64-bit integer to track total allocated memory.

[marcin-krystianc]

Rationale for this change

Fixes #47009

What changes are included in this PR?

ExportedAllocationOwner now uses a 64-bit (instead of 32-bit) variable to track total allocated memory.

Are these changes tested?

yes

Are there any user-facing changes?

This PR contains a "Critical Fix".
Previously, it wasn't possible to export Record Batches larger than 2GB, it resulted in overflowing the integer variable that was used to track allocated memory.

• GitHub Issue: [C#] Integer overflow in the ExportedAllocationOwner #47009

[github-actions]

Thanks for opening a pull request!

If this is not a minor PR. Could you open an issue for this pull request on GitHub? https://github.com/apache/arrow/issues/new/choose

Opening GitHub issues ahead of time contributes to the Openness of the Apache Arrow project.

Then could you also rename the pull request title in the following format?

GH-${GITHUB_ISSUE_ID}: [${COMPONENT}] ${SUMMARY}

or

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See also:

• Other pull requests
• Contribution Guidelines - Contributing Overview

[github-actions]

⚠️ GitHub issue #47009 has been automatically assigned in GitHub to PR creator.

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 7135199.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 47 possible false positives for unstable benchmarks that are known to sometimes produce them.