Summary

Finish implementation of WT_SESSION::create(import=()) with metadata_file option that imports multiple files in one go. It should work the same way as file_metadata option just for more than one file. This ticket will use what has been done in WT-9051 and WT-9052. To enable the import path for tiered storage we need to move the error added in WT-7736 to the place that allows execution with the metadata_file option.