fix(eventstore): use decimal, correct mirror (#9916)

# 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

internal/eventstore/event.go

@@ -5,6 +5,8 @@ import (
 	"reflect"
 	"time"
 
+	"github.com/shopspring/decimal"
+
 	"github.com/zitadel/zitadel/internal/zerrors"
 )
 
@@ -44,7 +46,7 @@ type Event interface {
 	// CreatedAt is the time the event was created at
 	CreatedAt() time.Time
 	// Position is the global position of the event
-	Position() float64
+	Position() decimal.Decimal
 
 	// Unmarshal parses the payload and stores the result
 	// in the value pointed to by ptr. If ptr is nil or not a pointer,