Merge topic 'multi-format-export'

c8997fc046 export: Allow depending on targets exported multiple times
7b553a3b1d cmExportInstallFileGenerator: Report errors with IssueMessage
6195cefcfe export: Convert ExportInfo to a struct with meaningful field names

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !10114