Catch DOM errors before merging PRs

[lorenzo-cavazzi]

We show DOM errors in the console while developing, but we don't enforce any test to fail on those occurrences.
Since we have already merged PRs with DOM errors in our codebase (E.G. clickable elements like anchors rendered inside other clickable elements), we should find a way to prevent that.

The most straightforward approach will be re-using tests to render elements (i.e. the Cypress tests) to catch those occurrences.
There are libraries that do that (E.G. https://www.npmjs.com/package/cypress-fail-on-console-error). If those work, it should require only minimal setup.
Otherwise, we might need to catch the console errors manually (E.G: Cypress.on('window:before:load', (win) => { cy.spy(win.console, 'error').as('consoleError'); }); ) and fail the test (cy.get('@consoleError').should('not.have.been.called');).