Table ad_track_event grows large very fast - should allow to be limited to clicks

Problem/Motivation

Table ad_track_event grows large very fast. Just after some days it has grown to 4.9 GB.
It should therefore allow to be limited to clicks only.

Also, we should inform users about this to be aware! Tracking every view is just far too much.

Steps to reproduce

Use event tracking on a highly frequented project and see the table grow extremely fast!

Proposed resolution

We will create a settings page for the ad_tack module with the following settings:

Totals tracking

• Track total impressions (Enabled via update hook)
• Track total clicks (Enabled by default)

Event tracking

• Track impression events (Enabled via update hook)
• Track click events (Enabled via update hook)

Event metadata

• IP address (Disabled)
• User agent (Enabled via update hook)
• URL (Enabled by default)
• Page title (Enabled by default)
• Referrer (Enabled by default)

[Clear event data] (Button to flush the ad_track_impression table)

Ideally the settings should already be taken into account in the JS library, so that, when neither total nor event tracking is enabled for an event type (click / impression), no request to the controller is made at all to save on performance.

There should also be a warning message on the settings page when the ad_track module is not enabled to inform the user of the fact. Warnings in the settings descriptions are also necessary for settings that may lead to performance impacts or huge storage increases on larger sites.

Remaining tasks

User interface changes

API changes

Data model changes