Consider to add the dedicated MediaType for the application zip

[mipo256]

In our application we use spring-web, and we sometimes serve the ZIP archives over the network. Unfortunately, MediaType does not have application/zip entry. For now, we have created this MediaType ourselves, but I think adding it would be although a small, but nice and type-safe option for all of the framework users to benefit from it.

I can also assist in implementation, if possible.

[rstoyanchev]

This has been discussed in #29072 and also in other issues for other media types. Generally we don't aim to have constants for all media types.