Set ChartData key to pod when prometheus metrics contain multiple keys

[ashutosh16]

Line chart does not render correctly when Prometheus response metrics contain multiple key/value pairs. As there are multiple keys, it is constructed very long name in the chartdata, causing render issue (possibly due to upstream issue in line chart). As a result, an if condition was added to filter pod names to only have one unique name. e.g

"metric": {
            "__name__": "namespace_argocd_pod_memory_usage_bytes",
            "assetId": "xx",
            "namespace": "sandbox-rollout-xx-x",
            "pod": "numalogic-rollout-x",
            "receive": "true",
            "tenant_id": "default"
        }