Parallelise reading IPMI over lanplus

[Spanfile]

Feature Request

Proposal:

The IPMI plugin reads metrics from all given servers sequentially. When reading many remote servers with lanplus, the total run time can easily reach many minutes if some servers are slower to read (I've seen up to 40 seconds on some). Change the plugin to read the servers in parallel to allow for more frequent reads.

Current behavior:

The plugin reads lanplus servers sequentially, causing a long run time with multiple servers.

Desired behavior:

The plugin reads each server in parallel, lowering the run time.

Use case: [Why is this important (helps with prioritizing requests)]

Having a higher granularity for sensor data helps with processing and analysing the data over time.