[WIP] use codecov orb instead of bash uploader

[crupley]

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As the result of the recent CodeCov security breach, it would be preferred to use a fixed version rather than automatically upgrade to another potentially insecure version.

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Add the CodeCov script to repo and execute the static version.

This is the advised solution from CodeCov in response to my email request:

We are working on a new version that will compile into binaries. For now you can vendor the bash script into your repo and execute it there. That way it will not change until/unless you update it.
Ticket: https://codecov.freshdesk.com/helpdesk/tickets/4907

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