OSV.dev end2end API test tool

[another-rex]

Currently, a lot of issues from osv.dev's API is being picked up by osv-scanner's end to end tests causing snapshot changes. This is not ideal from both osv-scanner and osv.dev's perspective.

We want to implement an API snapshot test utility¹ which can take a yaml config file (or a DSL if it's easier to maintain) containing requests (body, headers, and endpoint), and generate snapshots of the responses (with verbose pieces stripped out ²), and diffs when the snapshots are different)

After we have this utility, we can set up a snapshot bot similar to what currently exists in osv-scanner. (Though we might have some trouble with google cloud credentials, we'll figure that out when we get there).

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Footnotes

1. Written in go, as we will be eventually rewriting the API in go, so avoid extending the python tests further needlessly. ↩

2. Probably can copy the custom gjson code extension I made in osv-scanner which does this field stripping. ↩