Status output related to OBS configuration is prefixed with the string
"OBS" and added padding for enabled and disabled features. This padding
was not aligned between platforms.
By moving the padding and prefix decoration into its own function,
both elements are controlled in a single place. CMake scripts were
changed to use this new function `obs_status` instead of using CMake's
`message` function directly.
This prevents windres to catch up '-Wno-multichar' as an option which is
unknown to it. This flag was added in commit
aa0e64b7c9c331f69a73f56c9b7fcc4d27bd72df
