Rewrite instruction context dispatch in a more circuit-friendly manner

[nkaskov]

We need to double-check it with the research team, but we may want to handle some heavy instructions separate from the basic set. The current design includes custom handling for:

• keccak256
• All the Push instructions
• MLOAD
• MSTORE

Let's try to find an approach that will not require changes in the native algorithm structure. It's okay to adjust the compiler frontend by adding new custom features if required.