Merge topic 'clang-tidy-xcode-generator'

09b7ac7f67 strings: use single characters where possible
6aa9023700 string_view: use string_view literals in comparisons
1b60137b98 strings: combine string literals
e1b70d7286 cmCPackDragNDropGenerator: use a string instead of a stream for commands
f5d04b5bf0 cmStrCat: use where possible in Apple-specific sources
3af822cd8f cmXCode21Object: simplify streaming expression
c4f751604b cmLocalXCodeGenerator: return a default string
ce549909fb cmCPackPKGGenerator: remove unnecessary `.c_str()` calls
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !8660