Avoid optionals on fields influences variables

**Describe the bug**

Even though `avoidOptionals.inputValue` is `false`, variable types are generated without optionals.

**To Reproduce**

1. My GraphQL schema:

```graphql
type Query {
a(filter: [A!]): String
}
```

2. My GraphQL operations:

```graphql
query a($filter: [A!]) {
a(filter: $filter)
}
```

3. My `codegen.yml` config file:

```yml
avoidOptionals:
field: true
object: true

```

```ts
export type AQueryVariables = Exact<{
filter: Maybe>;
}>;
```

https://codesandbox.io/s/stupefied-paper-vjrm1?file=/types.ts

**Expected behavior**

It's still part of my InputType so this is expected

```ts
export type AQueryVariables = Exact<{
filter?: Maybe>;
}>;
```

**Environment:**

- OS:
"@graphql-codegen/add": "^2.0.1",
"@graphql-codegen/cli": "^1.17.8",
"@graphql-codegen/fragment-matcher": "^1.17.8",
"@graphql-codegen/typescript": "^1.17.9",
"@graphql-codegen/typescript-operations": "^1.17.8",
"@graphql-codegen/typescript-react-apollo": "^2.0.6",
- NodeJS: 14