Use HCP Consul and HCP Vault for the Consul and Vault clusters used in E2E testing. This has the following benefits:
* Without the need to support mTLS bootstrapping for Consul and Vault, we can simplify the mTLS configuration by leaning on Terraform instead of janky bash shell scripting.
* Vault bootstrapping is no longer required, so we can eliminate even more janky shell scripting
* Our E2E exercises HCP, which is important to us as an organization
* With the reduction in configurability, we can simplify the Terraform configuration and drop the complicated `provision.sh`/`provision.ps1` scripts we were using previously. We can template Nomad configuration files and upload them with the `file` provisioner.
* Packer builds for Linux and Windows become much simpler.
tl;dr way less janky shell scripting!
The `Metrics` suite uses prometheus to scrape Nomad metrics so that
we're testing the full user experience of extracting metrics from
Nomad. With the addition of mTLS, we need to make sure prometheus also
has mTLS configuration because the metrics endpoint is protected.
Update the Nomad client configuration and prometheus job to bind-mount
the client's certs into the task so that the job can use these certs
to scrape the server. This is a temporary solution that gets the job
passing; we should give the job its own certificates (issued by
Vault?) when we've done some of the infrastructure rework we'd like.
