add suport for proxy authorization headers

[bramrodenburg]

Description

Adds support for configuring a proxy authorization header.

This is needed for self-hosted deployments of Lightdash that for example leverage Google Identity Aware Proxy (IAP). See Lightdash docs here.

Example usage

from lightdash import Client


client = Client(
   instance_url="<instance url>",
   access_token="<lightdash api token>",
   project_uuid="<lightdash project uuid",
   proxy_authentication=f"Bearer <id token>",
)

print(client.list_models())