chore(azure sinks): refactor Blob code out of azure_common

[jlaundry]

Summary

As Blob Storage was the initial Azure sink, many of the Blob-specific components were created in the azure_common module.

This refactor simply moves the Blob code out, leaving azure_common with authentication (shared with azure_logs_ingestion), SAS token parsing, and connection string parsing (while currently only used by azure_blob, SAS tokens and connection strings are also available in Event Hubs, Queues, and Tables).

Vector configuration

N/A - no change to config.

How did you test this PR?

cargo vdev int test azure and soak test in my lab.

Change Type

• Bug fix
• New feature
• Dependencies
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Notes

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