Updated context to be used for HTTP request + refactoring

[PawelWMS]

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./SPECS/LICENSES-AND-NOTICES/data/licenses.json, ./SPECS/LICENSES-AND-NOTICES/LICENSES-MAP.md, ./SPECS/LICENSES-AND-NOTICES/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

• Expanded the use of context to pass it to our HTTP requests.
• Added a context nil check in azureblobstorage.go.
• Re-named cancelCtx to closeCtx to better reflect the purpose of some of our defer calls.
• 1 loop refactoring to use the for element := range someChannel loops.

Does this affect the toolchain?

No.

Associated issues

• Improve network behavior, use contexts instead of cancel channel #9251

Test Methodology

• Local tests.
• Full dev build.

[dmcilvaney]

While it seems slightly pointless, everywhere I look says to always defer cancelFunc(). By its nature it should always be safe to do so. In fact I believe go vet will actually flag any un-deferred cancel functions.

I think the best argument is that maybe today its ok, but what about in 6 months? A developer will see a context, and assume that we followed best practices. They will add a go routine that only exits on the cancel signal, and now we have a memory leak.

tldr, defer cancelFunc() is a really easy and safe way to ensure that a context is cleaned up no mater what code flow we end up following.

[dmcilvaney]

#9307 (comment) We should add a test here to check early cancel propagates correctly.