fix: send chunk_size instead of manually handling it

[Ian2012]

Description: Sned the chunk_size parameter to libcloud directly instead of manually handling it, avoiding errors such as ContentDecodeError and UnicodeDecodeError on gzip files. Closes: #457

JIRA: Link to JIRA ticket

Dependencies: dependencies on other outstanding PRs, issues, etc.

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2. Do thing B
3. Expect C to happen
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Merge checklist:

• All reviewers approved
• CI build is green
• Version bumped
• Changelog record added
• Documentation updated (not only docstrings)
• Commits are squashed

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solutions, hacks, quick-and-dirty implementations, concerns about
migrations, etc.

[openedx-webhooks]

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[bmtcril]

I feel like I tried this at some point and it didn't work as I expected it to. Have you made sure that you're getting chunks of the expected sizes?

[Ian2012]

No I didn't, and it didn't solve the problem.

Actually, it does, I was testing it with a different branch.