This epic tracks improvement tickets to the metadata scaling challenges WiredTiger faces with high ident counts, e.g. 1M, 10M.

This is intentionally separated from the dhandle scaling epic as the two concepts are related by separate. The metadata file scales with ident count, and active dhandles is tracking the number of open idents. A customer could have 10M idents, and a very low ~2000 active dhandle count.