Make TypeInfo for SkipCheckIfFeeless transparent, too (#2449)
The `SkipCheckifFeeless::IDENTIFIER` became transparent (ie was whatever
the inner signed ext was). This PR just makes the `TypeInfo` transparent
too, so that libraries that use said info to decode the data (ie subxt)
can behave identically whether or not the `SkipCheckifFeeless` wrapper
is used or not.
---------
Co-authored-by: Oliver Tale-Yazdi <[email protected]>