feat(component): add chart to render Forwarded destinations

  ## what
  - add Doughnut chart to render Forwarded Destinations
  - add legend label onClick event listener
    - This will be used for going to another to page that will display
      queries to the forwarded destination
    - NOTE: not implemented currently
  - add doughnut arc onClick event listener
    - This will be used for going to another to page that will display
      queries to the forwarded destination
    - NOTE: not implemented currently

  ## how
  - Render `Skeleton` when the data is loading
  - use a function to format data obtained from props

  ## why
  - to render Forwarded Destinations data as chart

  ## where
  - ./src/components/Charts/ForwardDestinations.tsx

  ## usage

src/components/Charts/ForwardDestinations.tsx

@@ -0,0 +1,132 @@
+import Box from '@mui/material/Box';
+import Card from '@mui/material/Card';
+import CardContent from '@mui/material/CardContent';
+import Grid from '@mui/material/Grid';
+import Skeleton from '@mui/material/Skeleton';
+import Typography from '@mui/material/Typography';
+import { ResponsivePie } from '@nivo/pie';
+
+import { nivoChartsDarkTheme } from '@utils/darkTheme';
+import { IForwardedDestinations } from '@utils/url/upstream.types';
+
+interface Props {
+  data: IForwardedDestinations | undefined;
+  isLoading: boolean;
+}
+
+/**
+ * Data format for Nivo Pie charts
+ */
+export interface PieChartDataFormat {
+  /**
+   * ID of the label
+   */
+  id: string;
+  /**
+   * Label of the entry to be displayed as
+   */
+  label: string;
+  /**
+   * Value of the label
+   */
+  value: number;
+  /**
+   * Colour used to display on the chart
+   */
+  // color?: string;
+}
+
+const defaultData: IForwardedDestinations = {
+  forward_destinations: {},
+};
+
+const ForwardedDestinationsChart: React.FC<Props> = (props: Props) => {
+  const { data, isLoading } = props;
+
+  const formatData = (entries: IForwardedDestinations = defaultData): PieChartDataFormat[] => {
+    return Object.entries(entries.forward_destinations).map(([key, value]) => ({
+      id: key.split('|')[0],
+      label: key.split('|')[0],
+      value,
+      // color: chartThemeColours[i % chartThemeColours.length],
+    }));
+  };
+
+  if (isLoading) {
+    return (
+      <Box sx={{ height: 400 }}>
+        <Skeleton variant='rounded' height='inherit' />
+      </Box>
+    );
+  }
+
+  return (
+    <Grid item sx={{ height: 400 }}>
+      <Card sx={{ height: 'inherit' }}>
+        <CardContent sx={{ height: 'inherit' }}>
+          <Typography variant='h5'>Upstream servers</Typography>
+          <ResponsivePie
+            // base
+            data={formatData(data)}
+            margin={{ top: 0, right: 160, bottom: 20, left: 0 }}
+            innerRadius={0.5}
+            padAngle={0.7}
+            cornerRadius={3}
+            sortByValue
+            valueFormat={(value) => `${value}%`}
+            //
+            // style
+            theme={nivoChartsDarkTheme}
+            borderWidth={0}
+            //
+            // arc labels
+            arcLabelsSkipAngle={15}
+            arcLabelsTextColor={{ theme: 'labels.text.fill' }}
+            //
+            // arc link label
+            enableArcLinkLabels={false}
+            //
+            // interactivity
+            activeInnerRadiusOffset={15}
+            onClick={(arcData, event) => {
+              alert(`onClick arc: '${arcData.id}'`);
+            }}
+            //
+            // legends
+            legends={[
+              {
+                anchor: 'top-right',
+                direction: 'column',
+                justify: false,
+                translateX: 100,
+                translateY: 0,
+                itemsSpacing: 15,
+                itemWidth: 90,
+                itemHeight: 10,
+                itemTextColor: '#999',
+                itemDirection: 'left-to-right',
+                itemOpacity: 1,
+                symbolSize: 10,
+                symbolShape: 'circle',
+                onClick: (legendLabel) => {
+                  console.log(legendLabel);
+                  alert(`clicked on label: '${legendLabel.label}'`);
+                },
+                effects: [
+                  {
+                    on: 'hover',
+                    style: {
+                      itemTextColor: '#fff',
+                    },
+                  },
+                ],
+              },
+            ]}
+          />
+        </CardContent>
+      </Card>
+    </Grid>
+  );
+};
+
+export default ForwardedDestinationsChart;