Support for optional language field

[ahmed-shehata]

Support for optional language field, currently we do not support multi-language countries, as the language is based on the sales channel, we need to have an optional language parameter that is passed to the SDK.

Expected Behaviour

AtlasSDK.configure({
      client_id: "CLIENT_ID",
      sales_channel: "SALES_CHANNEL",
      is_sandbox: false,
      lang: "de"
    });

Current Behaviour

There is no language parameter

AtlasSDK.configure({
      client_id: "CLIENT_ID",
      sales_channel: "SALES_CHANNEL",
      is_sandbox: false,
    });