Merge topic 'export-EXPORT-subcommand'

98b9f52 Help: Document export(EXPORT) in the cmake-packages manual.
a1d2bda Don't copy find_dependency in configure_package_config_file.
f4f6529 Help: cmake-packages: Add missing slash.
cbe7e8f export: Implement EXPORT subcommand (#9822)
Merge branch 'master' into next