Add Homebridge Prometheus Exporter

[lstrojny]

An exporter for Homebridge accessories.

Example output

# TYPE homebridge_valve_type gauge
homebridge_valve_type{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="WMR863",name="Washing machine",serial_number="000148086751",firmware_revision="02.72"} 3 1673964161494
homebridge_valve_type{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="TMM843WP",name="Tumble dryer",serial_number="000139813383",firmware_revision="02.72"} 3 1673964161494

# TYPE homebridge_valve_status_fault gauge
homebridge_valve_status_fault{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="WMR863",name="Washing machine",serial_number="000148086751",firmware_revision="02.72"} 0 1673964161494
homebridge_valve_status_fault{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="TMM843WP",name="Tumble dryer",serial_number="000139813383",firmware_revision="02.72"} 0 1673964161494

# TYPE homebridge_valve_active gauge
homebridge_valve_active{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="WMR863",name="Washing machine",serial_number="000148086751",firmware_revision="02.72"} 0 1673964161494
homebridge_valve_active{bridge="Miele Wäsche Bridge E8C3",device_id="00:B3:F1:A2:76:78",manufacturer="Miele",model="TMM843WP",name="Tumble dryer",serial_number="000139813383",firmware_revision="02.72"} 0 1673964161494