ci/fix: add lint rule to detect non-alphabetical struct field ordering in TOML/JSON parsing

[mds1]

Foundry's parseRaw()/parseToml()/parseJson() orders struct fields alphabetically when converting to ABI-encoded bytes. If Solidity struct fields aren't in alphabetical order, abi.decode() assigns values to wrong fields. This caused cannonPrestate and cannonKonaPrestate to be swapped in OPCMUpgradeV600.sol.

See: https://getfoundry.sh/reference/cheatcodes/parse-toml/#decoding-toml-tables-into-solidity-structs

This PR therefore adds a CI lint rule (check-struct-order.sh) that detects this issue. CI for the first commit on this PR should fail because the bug is currently on main. Then I will push the fix and CI should pass at which point we fully validated everything works and we can merge.

This PR also moves an existing shell test script to test/script/ for better organization, but the file was unchanged

[mds1]

As expected, the new check_struct_order failed in the first commit, and passed in the second commit (a regression test failed, and was fixed in the last commit, but the new check did pass). Here is what the first commit failed with

Checking TOML/JSON struct field ordering...

OK L2Chain (in src/libraries/MultisigTypes.sol)
OK AddGameInputWithChainId (in src/template/AddGameTypeTemplate.sol)
OK BlacklistGamesTaskConfig (in src/template/BlacklistGamesV140.sol)
OK BlacklistGamesTaskConfig (in src/template/BlacklistGamesV400.sol)
OK OPCMUpgrade (in src/template/OPCMUpdatePrestateV300.sol)
OK OPCMUpgrade (in src/template/OPCMUpdatePrestateV410.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV200.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV220toV410.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV300.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV400.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV410.sol)
OK OPCMUpgrade (in src/template/OPCMUpgradeV500.sol)
FAIL OPCMUpgrade (in src/template/OPCMUpgradeV600.sol)
  Fields are not in alphabetical order!
  Current order:  cannonPrestate cannonKonaPrestate chainId expectedValidationErrors 
  Expected order: cannonKonaPrestate cannonPrestate chainId expectedValidationErrors 

OK GameImplConfig (in src/template/SetDisputeGameImpl.sol)
OK SetRespectedGameTypeTaskConfig (in src/template/SetRespectedGameTypeTemplate.sol)
OK OPCMUpgrade (in src/template/boilerplate/OPCMTaskBase.template.sol)

[FAIL] Some structs have incorrectly ordered fields! See above for details.

To fix: Reorder the struct fields to be in alphabetical order.
This is required because Foundry's parseRaw()/parseToml()/parseJson()
orders keys alphabetically when converting to ABI-encoded bytes.

See: https://getfoundry.sh/reference/cheatcodes/parse-toml/#decoding-toml-tables-into-solidity-structs

Exited with code exit status 1