in_node_exporter_metrics: add buddyinfo collector

[l2dy]

Is your feature request related to a problem? Please describe. Unable to monitor kernel memory fragmentation with Fluent Bit.

Describe the solution you'd like Implement the buddyinfo collector.

Describe alternatives you've considered N/A

Additional context https://github.com/prometheus/node_exporter/blob/master/collector/buddyinfo.go