feat: Support passing JavaScript framework specific SDK init as second init parameter

[timfish]

This copies the approach used in @sentry/capacitor.

import * as Sentry from "@sentry/capacitor";
import { init as sentryAngularInit }  from "@sentry/angular";

// Init by passing the sibling SDK's init as the second parameter.
Sentry.init({
  dsn: "__DSN__",
}, sentryAngularInit);

This involves minimal code changes and is not a breaking change since to the 2nd parameter has a default of the browser init!

I've extended the react and vite example apps to use this approach.

Closes #506

[AbhiPrasad]

Great change! Reminder to also update the sentry docs!

[AbhiPrasad]

there is also @sentry/svelte, @sentry/ember, and @sentry/angular!

[timfish]

Indeed, although we don't have any example tests for those... yet 😁

I'm also aware that the examples don't actually tests the vue/react SDK functionality!