ABI: Add Router routing graviton tests

[michaeldiamant]

Problem

As of writing, pyteal does not implement graviton tests confirming ABI Router behavior. The story requests closing the gap by:

• Adding facilities in graviton + pyteal to support automated testing.
• Implementing at least 1 test that improves our correctness confidence.

Related: algorand/graviton#21 adds ABI routing tests to graviton. It's possible to imagine extending these facilities in pyteal.

Solution

Dependencies

Urgency

compiler_test.py offers baseline confidence because generated TEAL will change if a regression is introduced. So, the issue seems less dire than it may initially appear.

[tzaffi]

A couple of tasks that were mentioned in the graviton PR and are relevant to this issue:

• Add graviton ABI Routing functionality in PyTEAL via ABIContractExecutor and use it to test more realistic programs such as.
  • Ben's demo abi which includes reference and transaction type method arguments
  • Ben's Priority Queue

[tzaffi]

#634 which is a child pr of #600 introduces the RouterSimulation class and tests/integration/abi_router_test.py for testing the router.

I'm closing the issue now as #600 is expected to merged in to master in the next couple of days.