Add encoding extension for Wavin Sentio metrics

[zmoog]

Context

• Metrics collection is broken since the wavinsentio receiver is using the https://github.com/zmoog/ws (v1) package than only works with the discontinued backend.
• I want to build a metrics encoding extension from scratch.

Goal

• Build a new encoding extension to encode the new WS metrics from the new backend.

Impact

Without support for the new metrics format we're not collecting any WS metrics.

[zmoog]

• metadata
• extension
• factory
• config
• unmarshaler