fix: Break down large PouchDB.bulkDocs calls

[taratatach]

Large bulkDocs calls (i.e. with thousands of documents to save at
once) can be the source of crashes.

We're not sure if this comes from PouchDB or the logger calls with
each document but we've figured that creating smaller batches of
documents, logging them all at once and then saving the batch in
PouchDB prevents crashes.

It should also result in less I/O since we're making a lot less logger
calls.
To accommodate for these logging changes, we update our jq path
filter so it looks into batches for documents with the expected path.

Please make sure the following boxes are checked:

• PR is not too big
• it improves UX & DX in some way
• it includes unit tests matching the implementation changes
• it includes scenarios matching a new behaviour or has been manually tested
• it includes relevant documentation