Page feedback improvements

[chalin]

There are a number of improvements that could be done to the page-feedback feature. Given the issues that exist with analytics (blockers & consent), I'm not sure whether it's worth investing too much time here. Taking note nonetheless:

• i18n support for the yes and no responses (I thought that I'd seen an issue go by that reported this but I can't find it)
• Programmatic support for links into page URL, somewhat like the edit/view-page-source repo feature.