chore: API cluster summary improvement

[jy4096]

Get all the pipelines and isbsvcs at once instead of individual calls.
fixes:#1161

Example Response payload

{
    "data": [
        {
            "namespace": "numaflow-system",
            "pipelineSummary": {
                "active": {
                    "Healthy": 1,
                    "Warning": 0,
                    "Critical": 0
                },
                "inactive": 0
            },
            "isbServiceSummary": {
                "active": {
                    "Healthy": 1,
                    "Warning": 0,
                    "Critical": 0
                },
                "inactive": 0
            }
        },
        {
            "namespace": "default",
            "pipelineSummary": {
                "active": {
                    "Healthy": 2,
                    "Warning": 0,
                    "Critical": 0
                },
                "inactive": 1
            },
            "isbServiceSummary": {
                "active": {
                    "Healthy": 2,
                    "Warning": 0,
                    "Critical": 0
                },
                "inactive": 0
            }
        }
    ]
}