chore(evm): upgrade pushchain/evm to v0.5.1 on audit-fixes (port of #265)

[0xNilesh]

What

Ports PR #265 (cosmos/pushchain/evm v0.4 → v0.5.1) onto audit-fixes. Cherry-picked #265's net diff, then closed the additional v0.2.1 → v0.5.1 API gap that the cherry-pick didn't cover (audit-fixes was two minor evm versions behind main).

Design

• Fresh genesis, no upgrade handler. Coin-info is established by adding bank denom metadata for upc to DefaultGenesis; v0.5's EVM InitGenesis auto-derives coin-info from it via LoadEvmCoinInfo (no migration needed on a fresh chain).
• EVMChainID = 9000 (matches the localchain_9000-1 default chain id), denom upc / display pushchain.

Audit fixes preserved (where main diverged/dropped them)

• F-2026-17025 isContractDeployed — kept; reimplemented via the renamed Account.HasCodeHash() (identical !IsEmptyCodeHash semantics). main had reverted this to the unsafe length-only check.
• usigverifier — kept audit-fixes' single canonical address (0xEC..01); did not import main's dead NewPrecompileV2/0xCA backward-compat path.
• expected_keepers.go GetBallot/GetAdmin and DerivedEVMCall — preserved.

v0.5 API adaptations

• EVMKeeper.NewKeeper new signature (+keys map, ConsensusParamsKeeper, EVMChainID, authKeeperEVMWrapper)
• MakeConfig(EVMChainID)
• CallEVM gained gasCap *big.Int — updated interface, mock, and all call sites (pass nil)
• PostTxProcessing(..., core.Message{}, ...) (was nilable)
• statedb.Account.Balance → *uint256.Int
• erc20 NativePrecompiles moved to top-level genesis
• evidence precompile removed (package gone in v0.5.1; main never had it)
• ante unordered-tx wrapper; GetMempool/SetClientCtx/RegisterPendingTxListener server-interface methods
• removed dead utils/precompile; Makefile test targets run with -tags=test

Testing

• go build ./... ✓
• full root-module go vet -tags=test ✓ (all code + test files compile)
• full unit suite ✓ (app, all x/ keepers+types, precompiles/usigverifier, app/ante, app/upgrades)
• all 5 integration packages ✓ (uexecutor, utss, uvalidator, uregistry, upgrades) — exercise the coin-info-from-genesis path, CallEVM gasCap, and PostTxProcessing end-to-end

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