Update usage of warp and starknet utilities

[Hyodar]

The current version of warp does not provide some utilities for hardhat-warp anymore in the same way. The ones I catched were:

• callClassHashScript: Closest one currently seems to be runStarkNetClassHash, and the path here probably needs an artifacts/ first.
• warpEventCanonicalSignatureHash: Closest one currently seems to be warpEventCanonicalSignaturehash256, but it's not equivalent as shown by the return type being changed - is now a { low: string; high: string } instead of a string.

Besides this, there was an encoding issue I encountered - on a contract deployment which got an address and a uint as parameters, the expected encoding by the starknet module was [address, [low, high]], not [address, low, high] as would result from this:

hardhat-warp/src/transcode/encode.ts

Line 11 in ff87e9d

return types.flatMap((ty) => encode_(ty, inputs));

Calls worked as usual though.

Also, is the deployer supposed to be the first signer you get on ethers.getSigners()? It didn't seem to be the case when I tested it. Some tests rely on this and it may be good to keep this as a standard.