grafana: update to 7.3.1

What's new in Grafana v7.3
  Google Cloud Monitoring: Out of the box dashboards
  Shorten URL for dashboards and Explore
  Table improvements and new image cell mode
  New color scheme option
  SigV4 Authentication for Amazon Elasticsearch Service
  CSV exports for Excel

What's new in Grafana v7.2
  New date formatting options added
  Field options are out of beta!
    Added table column filters
    New field override selection options
  New transformations and enhancements
  Drag to reorder queries
  Inspect queries in Explore
  $__rate_interval for Prometheus
  Toggle parsed log fields
  Sensitive alert channel settings are now encrypted
  Grafana Enterprise features
    Report time range
    Organization-wide report settings
    Report grid layout
  What窶冱 new in other parts of the Grafana ecosystem
    ADX (Azure Data Explorer) plugin
    X-Ray data source plugin

(tnn)