In HippoBeanLinksVirtualBeanPropertyWriter, 'site' links don't work for mounts with other alias than 'site' and most likely 'site links' are redundant completely

AFAICS, in HippoBeanLinksVirtualBeanPropertyWriter there is a problem with the links for 'site' mounts. Namely, by default,

final Mount siteMount = requestContext.getMount(ContainerConstants.MOUNT_ALIAS_SITE);

will only work when there is a mount with alias 'site'. It might work for more mounts but then customers need to be aware about the very complex 'mapped aliases'. This doesn't seem something we want. Much easier is to assume the resourceapi is always a child mount of the site mount they belong to, so just use the parent mount.

However, I think there is no purpose in having site links at all. Namely, the site mount is only there to render the initial SPA template, and nothing more. The content is always fetched over the resourceapi calls. Hence, I think the 'site' links for now can be completely removed. Perhaps we might need them later on when we have a hybrid approach of an SPA and normal site pages, but I think we can handle this better when we need to support this. So for now, I suggest to remove the site links from HippoBeanLinksVirtualBeanPropertyWriter