Generate models for all components in swagger.json

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

I'm automating client generation for my APIs. However, not all models that are shared my services are directly used by endpoints, so Kiota isn't generating the models for them.

### Client library/SDK language

Csharp

### Describe the solution you'd like

Add a flag on `kiota generate --all-models` to enable generating models for all components in the swagger.json.

### Additional context

I'm generating my swagger.json using Swashbuckle.Swaggergen and adding in the models that aren't in endpoints using DocumentFilters

```
services.AddSwaggerGen(c =>
{
c.DocumentFilter>();
});
```

Start with the `kiota generate` command and the handling of components in the referenced `swagger.json`. Trace how models are selected for generation, then verify that an `--all-models` flag generates every model component while preserving the existing default behavior.

Written by the indexing model from the issue text.