Surface OAuth errors with request details in Dashboard

[rguldener]

Currently when something goes wrong in an OAuth flow (or token refresh) only a generic error is printed on the server logs of Nango server. No errors are visible in the dashboard.

We should surface errors from OAuth flows in the dashboard, along with the details of the API request that was made.
This makes developers who use Nango more independent, because it allows them to see the exact error response from the server.

I can currently think of 3 errors where this is relevant:

OAuth flow errors
We could show these on the integration details page, along with information such as the Connection-ID, timestamp, exact callback URL etc.

Token retrieval errors
We could show these on the integration details page, along with information such as the Connection-ID, timestamp, exact token fetch API request etc.

Token refresh errors
We could show these on the Connection details page, along with information such as the number of previous refreshes, refresh token, timestamp, exact token refresh API request etc.

[rguldener]

Closing this with the new activity tab. Can re-open if needed.