Support MultiValue + looping via frame pointers

[michaeldiamant]

Problem

With the introduction of frame pointer opcodes (algorand/go-algorand#4319), there's less friction to support scratch slot-based operations on the stack. The story requests identifying + implementing stack-base management of looping structures + MaybeValue/MultiValue marshalling using frame pointer opcodes.

Placeholder - Expect that most details need to be fleshed out as we pick up the story.

Solution

Dependencies

Urgency