Support display the `PalletError` type

[boundless-forest]

• [ ] Bug report
• [x] Feature request
• [ ] Support request
• [ ] Other

I've searched the substrate stackexchange, but found nothing helpful. Is it possible to display the wrapped error types in the polkadot apps? I did such a test to show the case.

Add a test error type TestError which wrap a VerificationError annotated with PalletError and TypeInfo. Then, create a mock pallet call to trigger this error.

The polkadot apps display like:

Of course, I can dig into the console to analyse the dispatch error code there. But it's would be best to have it diplayed by the apps.