SEO improvements

We need to add support for standard SEO/Social items like:

- [ ] SEO meta description and unique titles for each page
- [ ] canonical URLs for products and taxons
- [ ] Basic OpenGraph support
- [ ] Prices OpenGraph support
- [ ] Image OpenGraph support
- [ ] JSON-LD Products
- [ ] JSON-LD Breadcrumbs
- [ ] JSON-LD Organization