[v1.14] Add `progressTrace`, `writeChannelCongestion`, and `internalDatabaseSizes` to batches `stats`

[Strift]

This issue follows the changes related to Meilisearch v1.14.0 mega issue.

Description

Add progressTrace, writeChannelCongestion, and internalDatabaseSizes to batches stats.

Warning

Do not type the fields inside those objects. The fields can change in a breaking way.

For more context, see the related issues in Meilisearch:

• Progress trace & write channel congestion: Display details of indexing timings in batches meilisearch#5359
• Internal database size: Display the internal database sizes in the batches stats meilisearch#5463