message: [types] Adding constructor for account event
  Closes:
  Approved by: runtian-zhou
diff: @@ -212,6 +212,15 @@ pub struct AccountEvent {
  }
  impl AccountEvent {
  + // TODO: should only be used for libra client testing and be removed eventually
  + pub fn new(amount: u64, account: AccountAddress, metadata: Vec<u8>) -> Self {
  + Self {
  + amount,
  + account,
  + metadata,
  + }
  + }
  +
  pub fn try_from(bytes: &[u8]) -> Result<AccountEvent> {
  lcs::from_bytes(bytes).map_err(Into::into)
  }
  