Merge topic 'cmake-diagnostics-methods'

b8b0bf1f27 cmListFile: Use cmMakefile to issue messages
0b65420670 Diagnostics: Use command-line option forms in messages
436bfb628c Diagnostics: Add IssueDiagnostics methods

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !11848