Simplify poseidon usage

[illuzen]

shouldn't change any hashes, but simplifies Header definition

depends on the new qp-poseidon PR Quantus-Network/qp-poseidon#74

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Note

High Risk
Header and block-hash logic are consensus-critical; the PR relies on a fixed-hash regression test to prove behavior is unchanged after dependency and type-parameter refactors.

Overview
This PR drops the qp-poseidon wrapper across the workspace and wires qp-poseidon-core from a local path (../qp-poseidon/core, 1.5.0 in the lockfile). Call sites that only needed hashing/serialization now depend on core directly; qp-poseidon is removed from node, runtime, wormhole, mining-rewards, dilithium-crypto, and related Cargo.toml / feature lists.

The main API change is qp_header::Header: it goes from Header<Number, BlockHashHasher, StateHasher> to Header<Number, Hashing>, with all header roots and parent_hash as H256, Poseidon block hashing implemented inside qp-header via qp_poseidon_core, and Hashing (e.g. BlakeTwo256) only for state trie / extrinsics roots. Runtime, opaque types, frame-system mocks, and wormhole tests are updated to Header<BlockNumber, BlakeTwo256> and Hash = H256 instead of PoseidonHasher.

pallet-wormhole no longer requires ToFelts on balances, asset IDs, transfer counts, or account types—those bounds were tied to the old Poseidon pallet. Header stability is guarded by a test that pins a known devnet header hash rather than comparing two code paths.

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