Cabal should warn more strongly about outdated hackage indexes

Inspired by [this stack overflow issue](https://stackoverflow.com/q/73124091/15207568).

Cabal does warn about the package index being out of date, but that is all the way at the top and not very prominent.

I see a few avenues for improvement:

* use colors
* add empty lines before and after the warning
* add an extra warning if the latest version of a required package is lower than a version mentioned in the bounds

Especially the last point could make a huge difference in my opinion. Specifically, in the stack overflow question linked above the problem is that `cardano-wallet` requires `blockfrost-client-core>=0.4 && <0.5`, but the latest version in the index is `blockfrost-client-core-0.2.0.0`. In this case cabal could again strongly recommend that the user run `cabal update` at the end of the resolution phase.

Furthermore, I think the whole output is quite cluttered, but I will leave that for another issue in the future.