Handle sp_runtime::ModuleError substrate updates (#492)

* codegen: Handle new errors of type [u8; 4] with backwards compatibility

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Add comments about the compatibility of `DispatchError::Module`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Handle legacy cases appropriately

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Introduce `ModuleErrorType` for compatibility versioning

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Implement `module_error_type` helper

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Implement `quote::ToTokens` for `ModuleErrorType`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Rename new error to ArrayError

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Add strict checks for ModuleError

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Fix cargo fmt

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen, subxt: Expose the error's raw bytes to user

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* subxt: Update polkadot with ModuleErrorRaw

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* subxt: Rename `ModuleErrorRaw` to `ModuleErrorData`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* subxt: Expose method to obtain error index

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Rename `ModuleErrorRaw` to `ModuleErrorData`

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

subxt/src/lib.rs

@@ -81,6 +81,7 @@ pub use crate::{
         Error,
         GenericError,
         HasModuleError,
+        ModuleErrorData,
         RuntimeError,
         TransactionError,
     },