Persist hash function in Environment

[SkymanOne]

Originally raised by @cmichi

By default, ink! and corresponding tooling assumes that blake2 hasher is used. This is because it is default hasher set in pallet-system in substrate. It is quite possible that a chain can use a different hasher (like sha256or poseidon for ZKP).

This will cause an incorrect calculation of the metadata.

We need to introduce additional field in Environment trait that will persist a specific hasher used across the toolstack

### Tasks
- [ ] Introduce a hasher type/field in `Environment` trait
- [ ] Open issue in `cargo-contract` to use custom hasher or use the one specified in `Environment`
- [ ] Open issue in `contracts-ui` to validate that the correct hasher has been used