(EAI-152) check for change to chunkAlgoHash when updating embeddings

[yakubova92]

Jira: https://jira.mongodb.org/browse/EAI-152

Changes

• Previously, updateEmbeddedContent would re-chunk if the page content changed OR chunkAlgoHash changed since the date provided
• Now, it updates embedded content when the chunk algo has changed, even if there were no other changes to the page, essentially ignoring the since date provided

[mongodben]

see comment about caching.

and beyond that, sorry if i'm dense, but what changes are you making?

[mongodben]

see comment about the $lookup implementation

[mongodben]

see comment about typing

[nlarew]

A few small suggested tweaks + one question about the caching behavior

[nlarew]

We shouldn't have two describe blocks with the same title. Can you either combine into a single block or disambiguate them with more descriptive titles?

[yakubova92]

I created a more specific describe block for this for now, but this test file should be refactored. These test cases were placed in their own describe block bc the original describe block used mocks for the page and embedding stores and we are moving to using mongodb-memory-server. I created a ticket to capture that work - https://jira.mongodb.org/browse/EAI-935

[nlarew]

I'm not sure I understand the purpose of the chunkAlgoHashes caching here.

• We define an empty cache and only use it for this one call right after.
• That call only gets the current chunkPage function (that we import into this file)

It seems like the cache will never actually be used? Am I missing something?