lib/errors: switch to std Unwrap, Is, As
Created by: bobheadxi
Unify error assertions on standard library implementations, instead of cockroachdb implementations - the UnwrapOnce
in that library supports Cause
for back-compat, but Cause
can have many meanings it seems
Discussion: https://sourcegraph.slack.com/archives/CHXHX7XAS/p1649709835518209
Test plan
TODO