Added a `cookies` property accessor to the `BaseClient` class, which retrieves cookies from the `httpx` AsyncClient object and returns a `simnet.client.cookies.Cookies` object (which is a custom implementation of the `httpx.Cookies` class). Additionally, the initialization function was refactored to better support using cookies. Now, if `account_id` is not passed in, it will be retrieved from the cookies.
Moves all subdirectories from 'simnet/client' to 'simnet/client/components' and adds the `__all__` variable to all affected files.
This change is intended to improve code organization and make it easier to manage exported symbols from these modules.