[2.x] allow cookie value to be set in UI

I made a patch against the 7.x-1.x branch to allow configuration of cookie values for 'disagreed', 'agreed (show thank you banner)' and 'agreed'. Along with already configurable cookie name this allows ineroperability with similar modules on other sites. In our use case, we wanted it to be interoperable with the Complianz plugin for WordPreess.

We will be using D9 in due course, so probably will not work on a patch for 7.x-2.x.

New version of the same patch which also fixes minor code issues reported in #3194889: prop is not a function in eu_cookie_compliance_admin.js and #3194891: background color and text color do not work.

There was an error in the above patch. Try again.

New version of patch without code for background and text color.

New version of patch, removing from js/eu_cookie_compliance_admin.js

  $(function () {
    showHideThankYouFields($('#edit-eu-cookie-compliance-popup-agreed-enabled').attr('checked', 'checked'));
  });

This code checks or unchecks the checkbox in the admin UI. The old code using the deprecated prop() does not whereas the version using attr() does.

This is largely based on my own work so I hesitate to mark it 'reviewed'. However, it has been working in production, so I will mark it 'RTBC'.