[[inputs.zfs]] Add support for zpool status/state on Linux

### Use Case

Currently, the `zfs` input (specifically the `zfs_pool` metric) only has the `status` tag available on FreeBSD. With the current implementation of the `zfs_pool` statistics, you can access the status/health of the ZFS Pool with the `state` file in the pool folder.

As an example, to get the status of the `storage` pool, you'd get the contents of `//state`. Currently, all the current i/o info is fetched from `//iostats`, but this only is done with zfs 2.x. I'm not sure how you would go about adding support to get the pool status on zfs 1.x (since I run zfs 2.1.x on my server).

### Expected behavior

Linux versions of Telegraf don't support providing/exposing the status of a ZFS Pool

### Actual behavior

The status/state of the ZFS Pool is only available on FreeBSD via the `zpool` command.

### Additional info

_No response_

Start by locating the Telegraf zfs input's zfs_pool collection and the existing FreeBSD status handling. Compare the Linux pool files under //state and iostats, including the stated ZFS 1.x and 2.x differences. Done means Linux zfs_pool exposes pool status/state while preserving its existing I/O metrics, with coverage for the supported layouts.

Written by the indexing model from the issue text.