message: [pdsl_model] Add ExecutionEnv const constructor
diff: @@ -14,6 +14,12 @@ pub struct ExecutionEnv<State>{
  pub state: State,
  }
  +impl<State> ExecutionEnv<State> {
  + pub const fn new(state: State) -> Self {
  + ExecutionEnv { state }
  + }
  +}
  +
  impl<State> ExecutionEnv<State> {
  pub fn caller(&self) -> Address {
  ContractEnv::caller()
  