Chart for Grafana Dashboards

With FireFly's [Prometheus metrics](https://github.com/hyperledger/firefly/tree/main/internal/metrics) and the Grafana dashboard made as part of https://github.com/hyperledger/firefly-perf-cli/pull/26, it'd be great to include a separate Helm chart which includes one or more Grafana + Prometheus (and maybe in the future Loki) dashboards as `ConfigMaps` to be used with the Grafana Dashboards sidecar: https://github.com/grafana/helm-charts/blob/main/charts/grafana/README.md#sidecar-for-dashboards

The chart should offer the ability to customize the discovery label on the `ConfigMaps` the event of the operators using a custom label as part of using the https://github.com/grafana/helm-charts/blob/main/charts/grafana or https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack charts.