[REQ] [typescript-axios] Use generated enums in operations

Is your feature request related to a problem? Please describe.

When using API functions generated from this, I want to be able to also use the enum types. The enums are generated for models, but they should also be generated for operations too.

Describe the solution you'd like

Generate and use enum types in operations.

Describe alternatives you've considered

Just hard-coding the enum values when using operations, but that's not great.

Additional context

e.g.

findPetsByStatus: async (status: Array<'available' | 'pending' | 'sold'>, ...

should be

findPetsByStatus: async (status: Array<FindPetsByStatusStatusEnum>, ...
...
export const FindPetsByStatusStatusEnum = {
    Available: 'available',
    Pending: 'pending',
    Sold: 'sold'
} as const;
export type FindPetsByStatusStatusEnum = typeof FindPetsByStatusStatusEnum[keyof typeof FindPetsByStatusStatusEnum];

Start with the typescript-axios generator's operation parameter generation and compare it with the existing model enum generation. Trace the example findPetsByStatus output and determine where operation enum types and constants should be emitted. Done means generated operations use named enum types instead of inline string unions and expose the corresponding enum values.