Add sg db command to reset databases & create site-admin users
Created by: jhchabran
This pr adds:
sg db reset-redis
sg db add-user -name=foo
And renaned sg reset
to sg db reset-pg
.
Because of issues with the conf
package it includes a workaround to force its CONFIGURATION_MODE
to empty
until we fix https://github.com/sourcegraph/sourcegraph/issues/29222.