Fixes#6594#6711#6714#7567
e2e testing is still TBD in #6502
Before, we only passed the Nomad agent's configured Consul HTTP
address onto the `consul connect envoy ...` bootstrap command.
This meant any Consul setup with TLS enabled would not work with
Nomad's Connect integration.
This change now sets CLI args and Environment Variables for
configuring TLS options for communicating with Consul when doing
the envoy bootstrap, as described in
https://www.consul.io/docs/commands/connect/envoy.html#usage