* refact: Changes required for gorm v2
* refact: Add db.DB wrapper and refact all test fixtures to use it
Stop leaking the gorm abstraction within our unit tests.
* refact: Migrate direct calls to pq to pgx driver
The refactor will remove the remaining direct dependencies on
the pq driver which has been deprecated in favor of the pgx
driver.
It includes the addition of common.SqlOpen which is a wrapper around
sql.Open, which is needed to deal with the driver name changing from
"postgres" to "pgx" but in our code base the dialect and driver are
synonyms.
This adds new dimension table to record credential information. Since a
session can have multiple credentials, the wh_session_accumulating_fact
is is linked to the credential_dimensions via bridge tables,
wh_credential_group and wh_credential_group_membership. When a session
is inserted, the credental group and credential dimensions will be
upserted. If the group changed in any way, a new group is inserted along
with all of the corresponding credentials.