Add canonical tags to idea portal pages

Add canonical tags to pages which potentially count as duplicate content for Google Bots.

Pages like https://ideasportal.com/?category=7549147402332621549&cfo_id=7521749258644536743 count as the same page as https://ideasportal.com for Google Bots and thus get marked as duplicate content, when there is no canonical tag set and the Google Bot is not detecting the duplicate content by itself. The amount of detected duplicate content across our domain rose from 450 to 16000 after launching our ideas portal under a custom domain. Undetected duplicate content will most likely have bad impact on your SEO performance.

Add canonical tags that point to the original page on pages that potentially create duplicate content through e.g. URL parameters or pages like ideasportal.com/ideas.