Started implementing the sitemap module

- Added SitemapNode-related entities to the model.
- Added index, editor and translator in sitemap module.
- Updated some Nuget packages (bootstrap, font awesome)
Implemented the publishing of drafts

- Publish and republish drafts
- Show Publications in draft overview
- Model changes in SitemapNodeContent
- Misc details in sitemap and draft module
Implemented the republishing of drafts
Reviewed websiteMetadata, localization,...

- Moved infrastructure/entities to sitemap module
- Moved content of websiteMetadata to localization
- Renamed websiteInfo to WebsiteLocalization