This is a follow up of PLANET-3908 where we've added some configuration options to the footer social media icons, now I'd like to make two more changes:

Tasks
1. Add 2 more fileds in the CPP customizer for the footer items so that we have a total of 5
2. Rename 3 existing footer fields (Facebook, Instagram, Twitter) to: Footer item 1, Footer item 2... etc until 5 items
3. Add next to each URL fields an "Icon ID" field which should pull out the corresponding icon to shown in the footer
4. Pull the corresponding icon to each ID from the styleguide
5. Check campaign importer and exporter include the right values of the footer