fix[BE]: validate query page/limit defaults and add exists helpers

internal/modules/master/locations/controllers/location.controller.go

@@ -30,6 +30,10 @@ func (u *LocationController) GetAll(c *fiber.Ctx) error {
 		AreaId: c.QueryInt("area_id", 0),
 	}
 
+	if query.Page < 1 || query.Limit < 1 {
+		return fiber.NewError(fiber.StatusBadRequest, "page and limit must be greater than 0")
+	}
+
 	result, totalResults, err := u.LocationService.GetAll(c, query)
 	if err != nil {
 		return err