Add build time hook to extend webmanifest options

[igorexa34314]

I would like to have a build time hook that will be called before generating webmanifest to override its options. For instance if I want to extend site webmanifest with some values from runtimeConfig or have a more complex configuration (e.g. fetching manifest data from an API).

In result, I will be able to do something like this

nuxt.hooks.hook('pwa:beforeGenerateWebmanifest', async manifest => {
    manifest.name = nuxt.runtimeConfig.public.site.name;
    manifest.lang = nuxt.runtimeConfig.public.i18n.locale;

    // Perform some async operations related to webmanifest setup
    manifest.icons = await generateFavicons();
})