In #23966 we switched to the official Docker SDK for the `docker` driver. In the
process we refactored code around stats collection to use the "one shot" version
of stats. Unfortunately this "one shot" stats collection does not include the
`PreCPU` stats, which are the stats from the previous read. This breaks the
calculation we use to determine CPU ticks, because now we're subtracting 0 from
the current value to get the delta.
Switch back to using the streaming stats collection. Add a test that fully
exercises the `TaskStats` API.
Fixes: https://github.com/hashicorp/nomad/issues/24224
Ref: https://hashicorp.atlassian.net/browse/NET-11348
