Maciek Sakrejda

I'm marking this ready for review, since it's effectively complete. Sean volunteered to do the benchmark, but that shouldn't change things much.

Great, thanks for benchmarking! The `useLegacyFallback` param just [calls the old code](https://github.com/pganalyze/collector/pull/494/files#diff-b0823247f6e9e6c3f1033cc07a941a0435fea5c09f64ae4352b92b6ef8246614R358-R360) directly (to have an escape hatch in case there's an issue with the new code), so the perf...

Thanks for the review, @keiko713. Re: >Since logs are parsed more frequently than full snapshots, this means that it's possible to miss some logs after the log_line_prefix change until the...

Oh, and good call on the docs, although this is basically backward-compatible with the current docs, so we can update that later.

Tested successfully on RDS, self-managed, and Heroku.

Tested successfully on GCP (after a couple of fixes to the refactoring that was needed to use the new parser).

Thanks for testing, Keiko. I agree; let's handle that issue separately.

This change (allowing the app name regex to match brackets but making it non-greedy) fixes the problem and does not break the tests in the existing suite, but it needs...

Also, it looks like we're currently matching empty app names. I don't think that can actually happen: if you set your application_name to an empty string, the prefix lists '[unknown']...

I've added the test case to #494 (and it passes there), so I'll close this.