Merge cockroachdb#50377 cockroachdb#50900

50377: docs/RFCS: first draft of a sqlliveness RFC r=bdarnell,spaskob a=ajwerner

There's been a lot of back-and-forth over what we're trying to build and why.
Hopefully an RFC can help us to consolidate on terminology, goals, and
implementation details.

Release note: None

50900: publish-*artifacts: merge implementations of putRelease / putNonRelease r=jlinder a=otan

The `putRelease` / `putNonRelease` functionality of `publish-artifacts`
and `publish-provisional-artifacts` are almost exactly the same. I've
merged this to one implementation in the `release` package. This change
should have no functional difference to what is being published /
archived today.

I've also added the ability to put multiple files into a release archive
/ to be sent as part of a non release. This is relevant for a future
change, but getting that work bootstrapped here.

Release note: None

Co-authored-by: Andrew Werner <[email protected]>
Co-authored-by: Oliver Tan <[email protected]>