RoleManager.CreateAsync calls unsupported SetNormalizedRoleNameAsync

[cmsd2]

https://github.com/aspnet/Identity/blob/dev/src/Microsoft.AspNetCore.Identity/RoleManager.cs#L168

we don't allow the normalized role name to change for good reason,
but the role manager depends on this function succeeding.

also if the user has chosen a different ILookupNormalizer than the normal UpperInvariantNormalizer, the default initialisation of NormalizedRoleName in DynamoIdentityRole will not match the expected normalized role name.