Include add_payment_info and page_view events

[cdoe]

Typescript currently throws a fit when trying to log either the add_payment_info or page_view events with firebase.analytics.logEvent(). The error goes a little something like...

Argument of type '"add_payment_info"' is not assignable to parameter of type 'never'.

These two are the only default events without parameters and also don't have function overloads defined—meaning the following line assigns them to never.

firebase-js-sdk/packages/firebase/index.d.ts

Line 4336 in 07cd70d

export type CustomEventName<T> = T extends EventNameString ? never : T;

I think adding these two definitions patches things right up.

[hsubox76]

Thanks for the PR, you're right that we need to add those signatures. One small thing I'd like to ask for is to fill out the eventParams in each with event-appropriate suggested (optional) params, to provide useful autocomplete hints. (see code comments below)

I think that's it and then I will be happy to merge!

[hsubox76]

For page_view I think it should be:

eventParams: {
        page_title?: string;
        page_location?: string;
        page_path?: string;
        [key: string]: any;
      }

Source: https://developers.google.com/analytics/devguides/collection/gtagjs/pages

[cdoe]

Thanks for pointing that out, @hsubox76. New commit corrects those two eventParams. And sorry for some of the line-break weirdness. I think some extra spaces were included in my first commit that are now removed with this new one.

[hsubox76]

Looks good, thanks for the contribution!