Module does not support Vault agent only server

[sasudi90]

Hi,

It seems that this module does not support anything else than managing a Vault server and not a Vault Agent.

What are you seeing

The Vault service file does not support 'agent' mode yet, and if so it does not have configuration options for a particular agent.

What behaviour did you expect instead

I was hoping to see some Vault agent support, so we could manage the service and configuration file via this module.

Any additional information you'd like to impart

There has been a PR open to support the agent mode for solely the service file. PR here. Also, I gave a try to come up with a solution myself on this issue in PR #61 - as it's my first try ever please be gentle with me :')