🐛 Source Amazon Seller Partner: construct OAuth consent URL dynamically

[davydov-d]

This is a follow-up to this slack thread https://airbyte-globallogic.slack.com/archives/C02U9R3AF37/p1698760885839239

The Amazon Seller Partner source connector supports multiple regions. However, the only available auth method is OAuth and it's consent URL is hardcoded (1, 2) and leads to the US store developer app.

We need to construct the consent URL dynamically according to https://developer-docs.amazon.com/sp-api/docs/seller-central-urls. For reference, see this source code

[davydov-d]

cc @oustynova @katmarkham