feat: Add new Rhai example demonstrating payment flow

- Add a new Rhai example showcasing complete payment flow
  for company registration. This includes company creation,
  payment record creation, successful payment processing,
  status updates, and handling failed and refunded payments.
- Add new example demonstrating payment integration in Rhai
  scripting.  This example showcases the usage of various
  payment status methods and verifies data from the database
  after processing payments.
- Add new examples to Cargo.toml to facilitate building and
  running the examples.  This makes it easier to integrate
  and test payment functionality using Rhai scripting.

heromodels/src/models/mod.rs

@@ -14,7 +14,7 @@ pub mod projects;
 pub use core::Comment;
 pub use userexample::User;
 // pub use productexample::Product; // Temporarily remove
-pub use biz::{Sale, SaleItem, SaleStatus};
+pub use biz::{Payment, PaymentStatus, Sale, SaleItem, SaleStatus};
 pub use calendar::{AttendanceStatus, Attendee, Calendar, Event};
 pub use finance::marketplace::{Bid, BidStatus, Listing, ListingStatus, ListingType};
 pub use finance::{Account, Asset, AssetType};