[chore] Support a productFamily prop

[patricklafrance]

Currently, all predefined env endoints default to the Workleap Platform services. This is an issue for ShareGate products as they must provide the endpoint URLs by hand.

This issue is about introducing a productFamily property, allowing products to pick the right endpoint URLs.

Before:

import { initializeTelemetry } from "@workleap/telemetry/react";

const client = initializeTelemetry({
    logRocket: {
        appId: "my-app-id"
    },
    honeycomb: {
        namespace: "sample",
        serviceName: "my-app-name",
        apiServiceUrls: [/.+/g],
        options: {
            proxy: "https://sample-proxy"
        }
    },
    mixpanel: {
        productId: "wlp",
        envOrTrackingApiBaseUrl: "development"
    }
});

After:

import { initializeTelemetry } from "@workleap/telemetry/react";

const client = initializeTelemetry({
+   productFamily: "sg",  // default to "wlp" for backward compatibility.
    logRocket: {
        appId: "my-app-id"
    },
    honeycomb: {
        namespace: "sample",
        serviceName: "my-app-name",
        apiServiceUrls: [/.+/g],
        options: {
            proxy: "https://sample-proxy"
        }
    },
    mixpanel: {
        productId: "wlp",
        envOrTrackingApiBaseUrl: "development"
    }
});