Make example setup script

[antb123]

Many of the examples have hard coded testnet example addresses. So they may or may not run after a testnet upgrade.

Describe the solution you'd like Have it so a new user cold download the examples directory and then fully explore the scripts one by one for all common tasks

They may need to run a setup script (which creates accounts and asset codes beforehand).

Refactor the scripts so they can all be run unmodified after running a setup script.

Describe alternatives you've considered Leave as is