Add a workflow to upload binary size information to BigQuery

[kendalharland]

The first iteration of this workflow. Right now it can be triggered manually to enable backfilling for previous toolchain releases. In subsequent changes we'll make it run each time a release is created or updated.

Relies on two new actions:

• github.com/thebrowsercompany/gha-aws-ssm-get-parameter
• github.com/thebrowsercompany/gha-google-bloaty

[kendalharland]

I wonder if we could generalise some of this into a separate action and use that rather than start adding a ton of JS and composite actions into the repository.

Thinking about this more today: Yes we absolutely can, but I really want to validate the entire pipeline of sending data to BigQuery and Datadog before I put too much effort into refactoring this to be a reusable action - it might change quite a bit and working across repos will make things harder so I'd prefer to merge into this repo and iterate. How can I do this in a way that makes you happy? :)

Synced offline: I've already begun splitting this into separate repos.

[kendalharland]

Down to a ~280 line diff. In the future I may even pull out the bigquery upload csv code but I think it's too soon to know exactly what the API should look like without a few more example use cases

[kendalharland]

BTW, missing newlines on the python files.

Ah, thanks. Updated in the latest commit.