Replace uses of pg_authid with pg_roles so that crunchy_check_access ca…

[roberto-mello]

Replace uses of pg_authid with pg_roles so it can be used in Postgres instances where privileged catalog tables are restricted, such as public cloud providers (AWS)

[cbrianpace]

What versions of Postgres will this change support (how far back)?

[MichaelDBA]

@cbrianpace, replacing pg_authid with pg_roles and the columns they access goes back to at least PG 9.5.

[roberto-mello]

Had forgotten about this commit of mine from 3+ years ago... still open :-(

[keithf4]

Apologies for delays in reviewing this. Don't have a restricted system to test this in, but it's working fine in standard PG. Will pull this in and get a release done so you can test in the relevant environment