feat(eventstore): accept transaction in push (#8945)

# Which Problems Are Solved

Push is not capable of external transactions.

# How the Problems Are Solved

A new function `PushWithClient` is added to the eventstore framework
which allows to pass a client which can either be a `*sql.Client` or
`*sql.Tx` and is used during push.

# Additional Changes

Added interfaces to database package.

# Additional Context

- part of https://github.com/zitadel/zitadel/issues/8931

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

internal/eventstore/v3/unique_constraints.go

@@ -2,7 +2,6 @@ package eventstore
 
 import (
 	"context"
-	"database/sql"
 	_ "embed"
 	"errors"
 	"fmt"
@@ -11,6 +10,7 @@ import (
 	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/zitadel/logging"
 
+	"github.com/zitadel/zitadel/internal/database"
 	"github.com/zitadel/zitadel/internal/eventstore"
 	"github.com/zitadel/zitadel/internal/zerrors"
 )
@@ -24,7 +24,7 @@ var (
 	addConstraintStmt string
 )
 
-func handleUniqueConstraints(ctx context.Context, tx *sql.Tx, commands []eventstore.Command) error {
+func handleUniqueConstraints(ctx context.Context, tx database.Tx, commands []eventstore.Command) error {
 	deletePlaceholders := make([]string, 0)
 	deleteArgs := make([]any, 0)