Add `hashStruct()` for EIP-712 struct hash computation

Opening new issue as discussed here: https://github.com/ethereum/solidity/issues/14157#issuecomment-1537226011

## Abstract

Let's add function `type(S).hashStruct(s)` to compute `bytes32` hash from `S memory s` or `S calldata s` argument where `S` is struct compatible with EIP-712.

## Motivation

EIP-712 is pretty popular among Solidity projects, recently `typehash()` function were requested to be implemented here: https://github.com/ethereum/solidity/issues/14157. Having function to compute struct instance hash would be one more adoption step for this EIP.

## Specification

Implementation details could be borrowed form here: https://eips.ethereum.org/EIPS/eip-712

## Backwards Compatibility

Not required

Start by reading the linked discussion in issue #14157 and the EIP-712 specification, then trace the compiler entry points for the proposed type(S).hashStruct(s) function. Done means supporting memory and calldata struct arguments compatible with EIP-712 and producing the specified bytes32 struct hash, with coverage in the relevant compiler tests.

Written by the indexing model from the issue text.