[WCAG 2.1 / AA: 3.2.2] Do not dynamically change the page content on filtering forms

The WCAG 2.1 says that individual form inputs should not change the context of a web page. Only the submit button of a form should change the context as that is what users would be accustomed to on web pages. Another way is to advise the user in advance what the form does but I believe this would add unnecessary complexity to the view. In case the dynamic fields are kept, they should be marked with an aria-controls attribute indicating only the changed part. E.g. on the proposals page we cannot target the element with ID "proposals" with this as it has the sorting controls before the changed context starts. The implementation should be rethought if the dynamic filtering needs to be kept. Here's also one additional view about the aria-controls attribute: https://heydonworks.com/article/aria-controls-is-poop/ Currently the sidebar filtering forms e.g. on the proposals page do not meet the WCAG criteria on this.