We have many hand-written String() methods (and similar) for enums.
These require more maintenance and are more error-prone than using
automatically generated methods. In addition, the auto-generated
versions can be more efficient.
Here, we switch to using https://github.com/loggerhead/enumer, itself
a fork of https://github.com/diegostamigni/enumer, no longer maintained,
and a fork of the mostly standard tool
https://pkg.go.dev/golang.org/x/tools/cmd/stringer.
We use this fork of enumer for Go 1.20+ compatibility and because
we require the `-transform` flag to be able to generate
constants that match our current code base.
Some enums were not targeted for this change:
