Add histogram for insertion time to completion time

[bretthoerner]

Doh, plugin-server is deployed and sends the created_at field, but I forgot to consider that hooks-api wouldn't be serializing it into the DB until deployed, and so the race of deploying hooks-api and hooks-worker left rows that couldn't be deserialized in the DB.

Making this an Option as this field isn't critical to normal operation. I go ahead and set it in hooks-api if it's missing.

@xvello was right :)

Based on created_at column now.

[xvello]

The Job struct already has the created_at field sourced from PG, I suggest using it directly. As the submission through hooks-api is synchronous, its value should be pretty close to the source-submitted metadata. I am also wondering about the confusion factor of having a created_at column in the table + a created_at metadata, and what they mean.

[bretthoerner]

As the submission through hooks-api is synchronous

FWIW, my thinking was that a real end-to-end test takes into account any difficulties talking to the API (or if the API is blocked waiting on a PG connection from its pool, etc). In the end though I'm indifferent, and agree two created_at was a bad choice.

[bretthoerner]

Moving this to new repo to try out actions etc. PostHog/hog-rs#5