refactor(v2): init eventstore package (#7806)

* refactor(v2): init database package

* refactor(v2): init eventstore package

* add mock package

* test query constructors

* option based push analog to query

internal/v2/eventstore/postgres/storage.go

@@ -0,0 +1,28 @@
+package postgres
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/database"
+	"github.com/zitadel/zitadel/internal/v2/eventstore"
+)
+
+var (
+	_ eventstore.Pusher  = (*Storage)(nil)
+	_ eventstore.Querier = (*Storage)(nil)
+)
+
+type Storage struct {
+	client *database.DB
+}
+
+func New(client *database.DB) *Storage {
+	return &Storage{
+		client: client,
+	}
+}
+
+// Health implements eventstore.Pusher.
+func (s *Storage) Health(ctx context.Context) error {
+	return s.client.PingContext(ctx)
+}