Make DefaultClientInformationExtractor compatible with official Apollo clients

[pyrou]

According to Apollo documentation, and official implementation of Apollo clients (iOS, web, Android), client information are sent to GraphQL server using apollographql-client-name and apollographql-client-version headers.

This PR propose to accept these headers as fallback of x-apollo-client-name and x-apollo-client-version headers. to avoid need of writing custom ClientInformationExtractor.

Further reading :

• https://github.com/apollographql/apollo-ios/blob/7afcfc3c32950f7f6b6d768212f12412701ec7d6/Sources/Apollo/HTTPRequest.swift#L53-L54
• https://github.com/apollographql/apollo-client/blob/cbcf951256b22553bdb065dfa0d32c0a4ca804d3/src/link/http/createHttpLink.ts#L57-L60
• https://www.apollographql.com/docs/studio/client-awareness/#using-apollo-server-and-apollo-client

Backward compatibility:

• As new headers are used as fallback, this PR doesn't introduce breaking changes.

[MaartenStaa]

Looks good, thanks for your contribution and the links to the relevant sources. As the master branch is a work in progress for supporting Lighthouse v5, could you rebase your patch-1 branch onto 1.x?

[pyrou]

rebased. But I also need it in master, but I guess you'll also merge 1.x in it after :)

[MaartenStaa]

Done and done, thanks again!