On Demand self profile data

[rylev]

This moves fetching of self profile data from the database to s3. The self query data is still written to the database so that if we want/need to revert this, no data is lost.

This requires changes to the analyzeme crate (here rust-lang/measureme#200) which we may want to merge first before merging this.

[Mark-Simulacrum]

This requires changes to the analyzeme crate (here rust-lang/measureme#200) which we may want to merge first before merging this.

I don't think it's critical so long as we don't delete the upstream branch before we bump back to stable here; we don't carry the same need to keep commits building as in rust-lang/rust. But it would probably be nice for that to merge first.

[rylev]

@Mark-Simulacrum I tried this locally, and it seems to work. The local request runs slower than on production, but we're doing less work so I imagine that's just the difference between my laptop and the server running prod. Do we want to merge this now or wait for the analyzeme PR to merge?

[Mark-Simulacrum]

Let's go ahead and merge, so we can evaluate whether there's problems in production (not that we have metrics...). I don't think the branch is a huge hazard.