Merge topic 'improve_cmakes_error_handling_of_bad_parameters'

7302a23a1f cmake: Simplify -W recognition of no- and error= prefixes
98290782b6 cmake: redesign command-line argument parsing
d800c26ce9 cmake: Fix processing of -Wno-error= flags

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Axel Huebl <axel.huebl@plasma.ninja>
Merge-request: !5458