Add support to update extra parameters of the crash reporter.

[TimvdEijnden]

It's not possible to change the extra parameters of the crash reporter. For instance I'd like to add the user_id to the extra parameters but I have to fetch it from a webview first. Then I could add it to the extra parameters of the crash reporter. But I need to the crash reporter to start immediately so I don't miss reports.

I made an attempt, but it is too complicated for me as I don't have C++ experience:
#7072

My suggestion is to add a new method to the crash reporter:

crashReporter.setExtraParameters({
    'extra1': 'extra1',
    'extra2': 'extra2',
    'extra3': 'extra3'
})