LPS-46276 Refactoring and simplify to use ExportImportConfigurations

Hey Brian,

This change's purpose is mainly to be able to use the ExportImportConfiguration to kick off a staging or export process, and also to have only one configuration object per process instead of creating multiple.

In this commit: https://github.com/matethurzo/liferay-portal/commit/2efedbe02ebd4d9854bb12b5fa480c61f8d5a9dc on the first glance it might be more obvious if one copyRemoteLayouts method would call the other one with the ExportImportConfiguration parameter, but we need to validate the process first, and if the validation fails we should not create the configuration entity at all. That's why I went for the copyRemoteLayouts - doCopyRemoteLayouts pattern to reuse code.

Thanks,

Máté