Adds another exporter for Azure Health

[matzefriedrich]

This PR replaces the currently listed Azure Health exporter, as the repository appears to be no longer available.

The exporter produces gauge metrics as follows:

# HELP azure_resource_health_status Azure resource health status (1 = healthy, 0 = unhealthy)
# TYPE azure_resource_health_status gauge
azure_resource_health_status{resource_id="...",resource_name="...",resource_type="...",availability_state="Available"} 1

# HELP azure_resource_health_last_check_timestamp Timestamp of last health check
# TYPE azure_resource_health_last_check_timestamp gauge
azure_resource_health_last_check_timestamp{resource_id="...",resource_name="..."} 1.6984752e+09

[juliusv]

👍 Thanks!