Polkadot.js fails to decode dry run error with contracts-node v0.12.0

[statictype]

Polkadot.js fails to decode dry run error with contracts-node v0.12.0

To Reproduce

1. run the latest contracts-node in --dev mode (v0.12.0)
2. try to deploy a multisig
3. predicted outcome panel shows no values and I can move to the next step even though the dry run fails.
4. there is a console error

InstantiateContext.tsx:79 Error: createType(ContractInstantiateResult):: Struct: failed on result: {"_enum":{"Ok":"InstantiateReturnValueOk","Err":"DispatchError"}}:: Enum(Err):: Enum(Module):: Struct: failed on error: u8:: u8: Input too large. Found input with 28 bits, expected 8
    at createTypeUnsafe (type.js:56:1)
    at TypeRegistry.createTypeUnsafe (registry.js:288:28)
    at RpcCore._formatOutput (bundle.js:355:1)
    at RpcCore._formatResult (bundle.js:184:1)
    at callWithRegistry (bundle.js:209:1)

Expected behavior
the Predicted Outcome panel shows a ContractTrapped error because of the requirement being too low. Next button is disabled.

Additional context
Dry run works fine with contracts-node v0.11.0

[athei]

I think this is because the DispatchError type was changed by this PR.

The Module variant was changed. The error field is no longer an index (u8) but a 4 byte array that encodes the error using SCALE instead of relying on a lookup.

/// Old type
Module {
	index: u8,
	error: u8,
	message: Option<&'static str>,
}

/// New type
Module {
	index: u8,
	error: [u8; 4],
	message: Option<&'static str>,
}