[SUPER-TOKEN] Make compatible with current ethereum-contracts release

[philipandersson]

• Make compatible with current ethereum-contracts release
• Make sure new releases of ethereum-contracts validates examples to make sure we update examples as needed.
• Revamp of the project structure:
• multi-projects repo: e.g. hardhat-example/ hardhat full examples, and foundry-example/ minimum foundry example.
• migrate from truffle to hardhat for the main project.
• Make the pattern of defining ICustomSuperToken (See ISETHCustom as an example) explicit in all pure super token examples.
  • Some base functionalities are exposed through SuperToken self-functions, such as selfMint, selfBurn, selfTransfer, etc.
  • For the off-chain code, the CustomSuperTokenProxy address should be casted to the corresponding ICustomSuperToken interface to be useful.
• Adding an example of how to override existing SuperToken functions (e.g. GoodDollar overrides transfer)
• Adding an example where custom super token exempts from managed super token logic upgrade process:
  • This a necessary step before opt-in for an entire different deployment of custom super token logic.
  • Should this be even part of a new SuperToken factory option?
• Stretch goal: minimum CI.