v2 improve upload of captures

We are just experiencing the case where about 3000 captures are on the phone and 1700 still needed to be uploaded. This process even though the internet connection is pretty solid takes too long and is likely to be interrupted due to no indication of an uploading process going on. @Elforama is there a mechanism in place that the packs get uploaded in increments? I thought we had 50 leaving at a time or? Does the iOS have this functionality?

Start with the repository README and trace the Android capture-upload flow, since the issue names no files or tests. Determine how large batches are currently handled, how upload progress is surfaced, and whether the existing iOS behavior is a reference; done means a documented, agreed approach for reliable incremental uploads and progress indication.

Written by the indexing model from the issue text.