Provide a way to use the non-minified version of the cookie compliance JS

Problem/Motivation

It would be nice if users could choose whether to use the js/eu_cookie_compliance.js or js/eu_cookie_compliance.min.js, the former is very useful when developing.

Proposed resolution

Provide a UI option that switches between the minified JS and the non-minified version.

Remaining tasks

Provide MR.

User interface changes

New developer option in the settings page to use the non-minified JS.