Support new `ca` tracking parameter for tracking requests that aren't page views

[tsteur]

See matomo-org/matomo#16569 to learn more about the problem it fixes and visit https://developer.matomo.org/api-reference/tracking-api for more documentation about the new ca parameter.

Basically, we should be sending &ca=1 along any tracking request that isn't a page view. Practically, we should for now only send &ca=1 along any event and content tracking requests.

The parameter isn't required but it helps for more accurate tracking for edge cases where a user suddenly disables eg an event, goal or ecommerce plugin but still keeps sending these requests. If the parameter is not sent, Matomo would turn the tracking request into a page view and track a page view even though the tracking request should be ignored.

Let me know if there are any questions about this.