chore: minor adjustment to the Solidity verify() function signature and integration of Solidity verification with the CI

[weijiekoh]

This PR does two main things:

1. Change the ABI of the verify() function in Solidity to:

    function verify(
        uint256[] memory pubInputs,
        bytes memory proof
    ) public view returns (bool)

Previously, the size of pubInputs had to be specified. This change makes it easier for the CI tests to run as the number of inputs is not known at compile-time.

2. Enable Solidity verification in the CI

The CI flow now includes verification of the generated Solidity verifiers for the models which can be verified in Solidity (the others create contracts that are too large to work).

[alexander-camuto]

Added a few small comments regarding error handling, otherwise looks perfect !

[alexander-camuto]

LGTM !