Merge topic 'presets-error-diagnostics'

654a195d8b presets: Improve error diagnostics
c6e81bf30e Help/presets: Disallow empty env keys in build presets also

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Acked-by: scivision <michael@scivision.dev>
Merge-request: !11987