Add support for configuring the JSON unmarshal function used when querying SELECT_JSON statements.

tests/postgres/main_test.go

@@ -3,6 +3,7 @@ package postgres
 import (
 	"context"
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"github.com/go-jet/jet/v2/qrm"
 	"github.com/go-jet/jet/v2/stmtcache"
@@ -108,6 +109,16 @@ func allowUnusedColumns(f func()) {
 	f()
 }
 
+func useJsonUnmarshalFunc(unmarshalJson func(data []byte, v any) error, f func()) {
+	defer func() {
+		qrm.GlobalConfig.JsonUnmarshalFunc = json.Unmarshal
+	}()
+
+	qrm.GlobalConfig.JsonUnmarshalFunc = unmarshalJson
+
+	f()
+}
+
 var loggedSQL string
 var loggedSQLArgs []interface{}
 var loggedDebugSQL string