fix(eventstore): use decimal, correct mirror (#9914)

# Eventstore fixes

- `event.Position` used float64 before which can lead to [precision
loss](https://github.com/golang/go/issues/47300). The type got replaced
by [a type without precision
loss](https://github.com/jackc/pgx-shopspring-decimal)
- the handler reported the wrong error if the current state was updated
and therefore took longer to retry failed events.

# Mirror fixes

- max age of auth requests can be configured to speed up copying data
from `auth.auth_requests` table. Auth requests last updated before the
set age will be ignored. Default is 1 month
- notification projections are skipped because notifications should be
sent by the source system. The projections are set to the latest
position
- ensure that mirror can be executed multiple times

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

go.mod

@@ -45,6 +45,7 @@ require (
 	github.com/h2non/gock v1.2.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/improbable-eng/grpc-web v0.15.0
+	github.com/jackc/pgx-shopspring-decimal v0.0.0-20220624020537-1d36b5a1853e
 	github.com/jackc/pgx/v5 v5.7.5
 	github.com/jarcoal/jpath v0.0.0-20140328210829-f76b8b2dbf52
 	github.com/jinzhu/gorm v1.9.16
@@ -65,6 +66,7 @@ require (
 	github.com/riverqueue/river/rivertype v0.22.0
 	github.com/rs/cors v1.11.1
 	github.com/santhosh-tekuri/jsonschema/v5 v5.3.1
+	github.com/shopspring/decimal v1.3.1
 	github.com/sony/gobreaker/v2 v2.1.0
 	github.com/sony/sonyflake v1.2.1
 	github.com/spf13/cobra v1.9.1