Reuse collection_properties.idl for Shard Merge

The SERVER-61143 data structures WTImportArgs and CollectionImportMetadata could be replaced with the collection_properties.idl struct from the enterprise module, which we wrote for Live Import. This will require moving the IDL from the enterprise module to the main repo, and moving the buildStorageMetadata() calls from tenant_migration_shard_merge.cpp to wiredtiger_import.cpp.