Add variable value to be used for volume creation

### What feature do you want to see added?

I want to add a cache volume to improve performance at some internal operations that works better with an attached volume.
For example, if we have some I/O operations we want create a volume like:

`
type=volume, source=myvol-${docker-agent-count}, target=/internal
`

or any other identity that allow generate a volume for those docker agents and reuse only for them (not shared).
My plan is to use for docker-in-docker (/var/lib/docker) or apt cache folder (/var/cache/apt)

If the plugin allows 10 parallel docker agents to run ansible agents, it will generate 10 volumes:
- myvol-ansible-1
- myvol-ansible-2
...

### Upstream changes

_No response_