Extend Allwmake suggestions for possible problems

[MakisH]

This extend the Allwmake output to propose more ideas when something is going wrong during building. Inspired by recent topics on Discourse.

@DavidSCN do you think we should add anything else here?

TODO list:

• [x] I updated the documentation in docs/ -> N/A
• [x] I added a changelog entry in changelog-entries/ (create directory if missing) ~~-> Not sure if we really need one.~~ added

[davidscn]

A bit sad that it will take quite a while until these usability changes reach the user.