Migrate uwsgi/status MetricSet to ReporterV2

Migrate uwsgi/status MetricSet to ReporterV2: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). The uwsgi/status metricset under metricbeat/module/uwsgi/status is still using the legacy Fetch() interface that returns ( common.MapStr, error) . As part of the broader…