Update Zalo v4 api

[huyntt]

Update Zalo v4 API enpoint.

[martincostello]

• What are the benefits of changing to the v4 endpoint?
• Do you have a link to the v4 documentation?
• Does the user need to add any new settings to their app or configure anything in the portal to use it?

If we accept this change, the tests will need updating as in their current state they'll fail due to the stub HTTP requests no longer matching.

[huyntt]

Hi martincostello

The primary reason of change: without changes, current AspNet.Security.OAuth.Zalo fail to work.

There 2 changes are required to keep Zalo provider work properly.

1. Zalo v3 API endpoint was removed ref Zalo API annoucement . This cause ZaloAuthenticationDefaults.cs does not work since Nov 2021. Require to update endpoint.
2. Zalo API change request Get method to Post method and require add secret key in request header "secret_key: <your_secret_key>"
   ZaloAuthenticationHandler.cs

No additional settings are required from app side.

Reference doc:

• https://developers.zalo.me/changelog/v211001-cap-nhat-phuong-thuc-xac-thuc-5753
• https://developers.zalo.me/docs/social-api/tham-khao/user-access-token-v4

[martincostello]

Ok thanks, if it's completely broken with regards to the server side, then I guess there's no worries about breaking someone as they must have already been broken for a while 😅

Could you update the tests as required, then we can take the updates.