feat: add folder name to generate dashboard uid

[rzcastilho]

Change description

Adds the grafana folder name when configured, to the dashboard uid.

What problem does this solve?

Prevents dashboard override in grafana in different folder names, and open the possibility to have dashboards of the same type to the same grafana for diferent enviromnets of the same application, for instance when you have dev/staging/production environments.

Issue number: (if applicable)

Example usage

...
  config :app_name, AppName.PromEx,
    disabled: false,
    manual_metrics_start_delay: :no_delay,
    drop_metrics_groups: [],
    grafana: [
      host: System.get_env("GRAFANA_HOST"),
      auth_token: System.get_env("GRAFANA_TOKEN",),
      upload_dashboards_on_start: true,
      folder_name: "App Name (#{app_env})",
      annotate_app_lifecycle: true
    ],
    metrics_server: :disable
...

Additional details and screenshots

Checklist

• I have added unit tests to cover my changes.
• I have added documentation to cover my changes.
• My changes have passed unit tests and have been tested E2E in an example project.