Pull KVP on a post request

[cadejacobson]

This PR better mirrors the behavior found on the real Wireserver for pulling KVP that is written to the guest OS.
Previously, the pipeline would output the final KVP file directly from the Azure-init container which contained more information than what would be read in the real POST to Wireserver.

Now, when Azure-init reports ready to the Wireserver, the mock server will access the shared KVP log directly and make a copy, storing it locally. Upon the completion of the pipeline, this copied file is now outputted, giving a more accurate reading of what Wireserver actually sees in the KVP file.

How to use

No usage, this is done automatically by the pipeline during each PR.

[cjp256]

sharing all of /tmp seems a bit excessive for rw, I would probably suggest limiting to a particular directory specific for these tests (emptied prior to test)

[cjp256]

it looks like docker supports a tmpfs volume that should be perfect

[cadejacobson]

When checking the Docker tmpfs documentation, it shows a limitation as not being able to share access across containers, as it is only available in one container. The two services here are run in different containers, so this will cause an issue when trying to pull the KVP logs from the mock server. I will update the code to have access to only a single /tmp/testinit/ folder, though, to avoid the braod /tmp/ access.

[peytonr18]

This looks great!