@goField directive is ignored on Query/Mutation arguments

@goField directive is ignored on Query/Mutation
arguments but works on Input type fields

## Description

The `@goField` directive with `type` parameter
behaves inconsistently between direct Query/Mutation
arguments and Input type fields. When applied to
Query/Mutation arguments, the directive is silently
ignored, but it works as expected on Input type
fields.

## Current Behavior

### 1. Direct Query/Mutation arguments - NOT WORKING
❌
```graphql
type Query {
getUser(id: ID! @goField(type:
"domain.UserID")): User
}

Generated resolver:
// Expected:
func (r *queryResolver) GetUser(ctx context.Context, id domain.UserID) (*User, error)
// Actual:
func (r *queryResolver) GetUser(ctx context.Context, id string) (*User, error)

The @goField(type:"...") directive is completely
ignored.
```

### 2. Input type fields - WORKING ✅

```graphql
input GetUserInput {
id: ID! @goField(type: "domain.UserID")
}

type Query {
getUser(input: GetUserInput!): User
}

Generated model:
type GetUserInput struct {
ID domain.UserID `json:"id"` // ✅ Custom type
is correctly applied
}
```

Please let me know if there's a recommended way to map
Query/Mutation arguments to custom Go types.