Replace kunstmaan/google-api-custom with official google package

[acrobat]

Currently we're using a custom fork of the google api php client, but this package is lagging behind on the official package and users can't install the google package next to it because of conflicting namespaces. Try to remove the kunstmaan/google-api-custom package and depend on the google/apiclient package instead.

[tarjei]

Hi, I would just like to vote for this issue!Any ideas on what is needed to be done?

[acrobat]

A few thing are needed here:

• Replace kunstmaan/google-api-custom package with google/apiclient and see what the incompatibilities are.
  • Check which bc breaks there are and if we can change the code in a way to support both libs but deprecate the old one.
• Most of the implementation changes will need to change in the dashboard bundle (the google analytics widget)

So as a first step we need to get an overview of places in the code that need changes and if we can do these changes without breaking BC

[acrobat]

Related to #3245