Merge topic 'cleanup-define_property' into release-3.23

87c3b5e421 define_property(): Only test prefix if INITIALIZE_FROM_VARIABLE is given
9b50f221f6 Help: Update the main purpose of define_property()
e993e2c52c Help: Clean up INITIALIZE_FROM_VARIABLE define_property() option

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Acked-by: Kyle Edwards <kyle.edwards@kitware.com>
Merge-request: !7090