fix(nuxt-bridge): add support for nuxt bridge

[Jamiewarb]

Providing an Apollo Client

Nuxt Bridge exposes the Nuxt 2 context via nuxtApp.nuxt2Context.
However, when assining the apolloProvider to app.apolloProvider, the apolloProvider is not added to this context. (https://github.com/nuxt-community/apollo-module/blob/master/lib/templates/plugin.js#L115)

In order to get the apolloProvider onto this nuxt2Context, we must use inject().
However, it requires a different name than "apolloProvider" when injecting, or we get errors.

With these changes, it's now possible to provide the apollo client as before:

// layouts/default.vue
<script setup>
import { provideApolloClient } from '@vue/apollo-composable';

provideApolloClient(useNuxtApp().nuxt2Context.$theApolloProvider?.defaultClient);
</script>

Once the replacement for onGlobalSetup() is added, we can move this code back to a plugin: nuxt/framework#2408

Note: This is a short term solution for Nuxt Bridge, and will need revisiting Nuxt 3.