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>

internal/eventstore/search_query_test.go

@@ -106,10 +106,10 @@ func TestSearchQuerybuilderSetters(t *testing.T) {
 		{
 			name: "set columns",
 			args: args{
-				setters: []func(*SearchQueryBuilder) *SearchQueryBuilder{testSetColumns(ColumnsMaxSequence)},
+				setters: []func(*SearchQueryBuilder) *SearchQueryBuilder{testSetColumns(ColumnsMaxPosition)},
 			},
 			res: &SearchQueryBuilder{
-				columns: ColumnsMaxSequence,
+				columns: ColumnsMaxPosition,
 			},
 		},
 		{